ATI US Equity☆

ati-20251228

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 28, 2025

OR

For the transition period from to

Commission file number 1-12001

ATI Inc.

(Exact name of registrant as specified in its charter)

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (800) 289-7454

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol Name of each exchange on which registered

Common stock, par value $0.10 ATI New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the Registrant is well known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes☒ No ☐

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐No☒

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months, and (2) has been subject to such filing requirements for the past 90 days. Yes☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer ☒ Accelerated filer ☐

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statement. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

On January 30, 2026, the Registrant had outstanding 136,936,299 shares of its Common Stock.

The aggregate market value of the Registrant’s voting stock held by non-affiliates at June 29, 2025 was approximately $12.0 billion, based on the closing price per share of Common Stock on June 29, 2025 of $86.80 as reported on the New York Stock Exchange. Shares of Common Stock known by the Registrant to be beneficially owned by directors and officers of the Registrant subject to the reporting and other requirements of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are not included in the computation. The Registrant, however, has made no determination that such persons are “affiliates” within the meaning of Rule 12b-2 under the Exchange Act.

Documents Incorporated By Reference

Selected portions of the Proxy Statement for the Annual Meeting of Stockholders to be held on May 14, 2026 are incorporated by reference into Part III of this Report.

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INDEX

PageNumber

PART I

Item 1. Business 3

Item 1A. Risk Factors 8

Item 1B. Unresolved Staff Comments 16

Item 1C. Cybersecurity 16

Item 2. Properties 17

Item 3. Legal Proceedings 18

Item 4. Mine Safety Disclosures 18

PART II

Item 6. [Reserved] 20

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 37

Item 8. Financial Statements and Supplementary Data 39

Item 9A. Controls and Procedures 87

Item 9B. Other Information 90

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 90

PART III

Item 10. Directors and Executive Officers of the Registrant 90

Item 11. Executive Compensation 90

Item 14. Principal Accountant Fees and Services 91

PART IV

Item 15. Exhibits, Financial Statements and Financial Statement Schedules 91

SIGNATURES

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PART I

Item 1. Business

The Company

ATI Inc. is a Delaware corporation with its corporate headquarters located at 2021 McKinney Avenue, Suite 1100, Dallas, TX 75201, telephone number (800) 289-7454, Internet website address www.atimaterials.com. Our Internet website and content contained therein or connected thereto are not intended to incorporate into this Annual Report on Form 10-K. References to “ATI,” the “Company,” “the Registrant,” “we,” “our” and “us” and similar terms mean ATI Inc. and its subsidiaries, unless the context otherwise requires.

When used in this Annual Report on Form 10-K, unless the context otherwise requires or unless otherwise specified, any reference to “year” is to the Company’s fiscal year. The Company follows a 4-4-5 or 5-4-4 fiscal calendar, whereby each fiscal quarter consists of thirteen weeks grouped into two four-week months and one five-week month, and its fiscal year ends on the Sunday closest to December 31. Fiscal years 2025, 2024 and 2023 ended on December 28, 2025, December 29, 2024, and December 31, 2023, respectively. All fiscal years presented include 52 weeks of operations.

Our Business

ATI produces specialty materials, highly differentiated by our materials science expertise and advanced process technologies. Our mission is to solve the world’s challenges through materials science. Aerospace & defense, our largest end markets, represent approximately 68% of total sales, led by products for jet engines and airframes in addition to a wide range of defense applications. Additionally, we have a strong presence the specialty energy market and also serve customers in several other markets including conventional energy, medical, electronics and other industrial markets.

We operate in two business segments: High Performance Materials & Components (HPMC) and Advanced Alloys & Solutions (AA&S). HPMC produces a wide range of high performance materials, components, and advanced metallic powder alloys. These products are made from nickel-based alloys and superalloys, titanium and titanium-based alloys, and a variety of other specialty materials. HPMC’s capabilities range from cast/wrought and powder alloy development to production of highly engineered finished components, and 3D-printed aerospace products. The HPMC segment’s primary focus is on maximizing jet engine materials and components growth, with approximately 92% of its revenue derived from the aerospace & defense markets, including nearly 68% from products for commercial jet engines. Commercial aerospace products have been the main source of sales and EBITDA growth for HPMC over the last several years and are expected to continue to drive HPMC and overall ATI results in the future. HPMC has also experienced strong growth in defense products, with fiscal year 2025 sales growth of 24%. Sales of defense products comprise almost 11% of HPMC's total sales.

The AA&S segment produces nickel-based alloys, titanium and titanium-based alloys, and specialty alloys, including zirconium, hafnium, and niobium, in a variety of forms including plate, sheet, and strip products. AA&S focuses on high-value materials that are utilized in technically challenging and extreme environments, which require materials that can withstand extreme heat, radiation and corrosion. AA&S continued its focus of growing sales to the aerospace & defense end markets, with fiscal year 2025 sales to those markets increasing 15%. Aerospace & defense now comprises approximately 41% of AA&S total revenue. AA&S also serves customers across several other markets, notably specialty energy and conventional energy, as well as electronics and certain industrial markets.

End-use markets for our products include:

Aerospace & Defense. We are a world leader in the production of specialty materials and components for both commercial and military jet engines and airframes, supporting customer needs for initial build requirements and for spare parts. We believe that through alloy development, internal growth efforts, and long-term supply agreements on current and next-generation jet engines and airframes, we are well-positioned with a fully qualified asset base to meet the expected multi-year demand growth from the commercial aerospace market.

Nickel-based alloys and superalloys remain extremely strong at high temperatures and resist degradation under extreme conditions. Next-generation jet engines use advanced nickel-based superalloys and metallic powder alloys to enable increased fuel efficiency requirements that require hotter-burning engines. Typical aerospace applications for the nickel-based alloys and superalloys and advanced metallic powders we produce include jet engine disks, blades, vanes, rings, casings and shafts. Our specialty materials are also used in the manufacture of aircraft landing gear and structural components.

We are a global industry leader in iso-thermal and hot-die forging technologies for advanced aerospace components. We produce highly sophisticated components that have differing mechanical properties across a single product unit and are highly resistant to fatigue and temperature effects. Our precision forgings are used for jet engine components, structural components

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for aircraft, helicopters, space propulsion, and other demanding applications. ATI provides a full range of post-production inspection and machining with the certified quality needed to meet demanding application requirements.

Additionally, the products and components made from the titanium and titanium-based alloys we produce, such as jet engine components including disks, blades and vanes, and airframe components such as structural members, landing gears, and hydraulic systems, are also critical in aerospace applications. These materials and components possess an extraordinary combination of properties that help to increase jet engine fuel efficiency and product longevity, including superior strength-to-weight ratios, elevated temperature resistance, low coefficient of thermal expansion, and extreme corrosion resistance.

We produce a wide-range of military-grade materials including titanium, nickel-based alloys, zirconium, tungsten, and hafnium, as well as components for our defense customers. Our materials and components are used for many applications, including naval nuclear products, military jet engines, fixed wing and rotorcraft products, armor applications and munitions materials. In fiscal year 2025, sales to our defense end market increased by 14% and we expect continued growth in this important end market in the coming years.

We continuously seek to develop and manufacture innovative new alloys to better serve the needs of the aerospace & defense markets, and several of the alloys we produce have won significant share in current and next-generation jet engines. ATI’s metallic powder technology delivers alloy compositions and refined microstructures that offer increased performance and longer useful lives in high-temperature aerospace environments, as well as improved jet engine efficiency. We continue to increase our production capacity for advanced metallic powders for use in next-generation aerospace products, including additive manufacturing applications. ATI also has a dedicated additive manufacturing and post-processing facility to tap into significant aerospace & defense demand for additively manufactured laser powered bed fusion parts, serving both commercial and defense customers.

Energy. Our products are sold to a variety of end customers in the end-use energy market, with a focus on specialty energy, which includes nuclear power generation and gas turbines.Our high-performance products meet a wide range of needs for protection, conductivity, thermal performance and corrosion resistance. ATI's solutions for the energy industry include specialty materials for solar, geothermal and wind applications, reactor-grade zirconium and hafnium alloys, pioneered by ATI, for nuclear plants; and corrosion-resistant alloys for water systems and scrubbers in coal plants. We believe clean energy needs, the electrification of developing countries, and energy requirements to support data center growth will continue to drive demand for our specialty materials and products for use in these industries over the long term.

Further, we are an industry pioneer in producing nuclear reactor fuel cladding and structural components utilizing zirconium and hafnium alloys for use in nuclear power generation. We also are a technology leader for large diameter components used in natural gas land-based turbines for power generation, and our alloys are used for alternative energy generation, including solar, fuel cell, wind and geothermal applications.

Both of our business segments also produce specialty materials that are critical to the conventional energy market, which includes the oil and gas and chemical and hydrocarbon processing industries. The environments in which oil and gas can be found in commercial quantities have become more challenging, involving deep offshore wells, high pressure and high temperature conditions in sour wells, and other unconventional sources. These challenging offshore environments are located further off the continental shelf, including locations in arctic and tropical waters where drilling is more difficult than previously-sourced locations. Our specialty materials, including nickel-based alloys, duplex alloys and other specialty alloys, have the strength and corrosion-resistant properties necessary to meet these challenging operating conditions. We enable our customers’ success in these applications by developing and producing specialty materials for equipment that can operate for up to 30 years in these harsh environments.

Other Markets. We also serve several other customer end markets, including electronics, medical, and industrial. Customers in the medical end market use ATI’s advanced specialty materials in medical device products that enhance the quality of lives around the world. Manufacturers of magnetic resonance imaging (MRI) devices rely on our niobium superconducting wire to help produce electromagnetic fields that allow physicians to safely scan the body’s soft tissue. Our specialty alloys also are used for replacement knees, hips and other prosthetic devices. The use of our alloys in these replacement devices offers the potential for longer product lifespans versus previous implant generations. Our biocompatible nickel-titanium (nitinol) shape memory alloy is used for stents to support collapsed or clogged blood vessels.

In the electronics market, nickel alloys and Precision Rolled Strip® (PRS) from Specialty Rolled Products (SRP) and our Asian PRS joint venture are used in computers and smart phones. PRS is selected for electronics and communications applications based on corrosion resistance, strength, wear resistance, electrical resistivity or thermal expansion. In addition, metal precursors – which use chemicals produced by ATI, such as hafnium – have a variety of important applications in consumer and industrial electronics.

Finally, ATI's materials and products are used across a wide range of industrial markets, including automotive and construction and mining.

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Business Segments

Our two business segments accounted for the following percentages of total revenues of $4.6 billion, $4.4 billion, and $4.2 billion for the fiscal years ended December 28, 2025, December 29, 2024, and December 31, 2023, respectively.

Fiscal Year Ended

High Performance Materials & Components 53 % 52 % 51 %

Advanced Alloys & Solutions 47 % 48 % 49 %

Information with respect to our business segments is presented below and in Note 18 of the notes to the consolidated financial statements.

High Performance Materials & Components Segment

Our HPMC segment produces a wide range of high performance specialty materials, parts and components for our aerospace & defense, specialty energy, and medical markets, with approximately 92% of fiscal year 2025 revenues derived from the aerospace & defense markets. Most of the products in this segment are sold directly to end-use customers, and a substantial portion of our HPMC segment products are sold under multi-year agreements. Demand for our products is driven primarily by the commercial aerospace cycle. Large aircraft and jet engines are manufactured by a small number of companies, such as The Boeing Company (Boeing), Airbus S.A.S. (an Airbus Group company) including the former operations of Bombardier Aerospace, and Empresa Brasileira de Aeronáutica S.A. (Embraer) for airframes. GE Aerospace, Rolls-Royce plc, Pratt & Whitney (a division of Raytheon Technologies Corporation), and Safran Aircraft Engines. These companies and their suppliers form a substantial part of our customer base in this business segment. We have long-term agreements (LTAs) in place with most major aerospace market original equipment manufacturers (OEMs). The loss of one or more of our customers in the aerospace or defense markets could have a material adverse effect on ATI’s results of operations and financial condition (see Item 1A. Risk Factors).

Within this segment, our products are manufactured from a wide range of advanced materials including metallic powder alloys made from nickel-based alloys and superalloys, titanium and titanium-based alloys, and a variety of other specialty materials. These materials are made into a variety of product forms that include precision forgings, machined parts and others. We are integrated across these alloy systems in melt, forging, finishing, testing and machining processes.

Principal competitors in the HPMC segment include: Berkshire Hathaway Inc., for nickel-based alloys and superalloys and specialty steel alloys, titanium and titanium-based alloys, and precision forgings through its ownership of Precision Castparts Corporation and subsidiaries; Howmet Aerospace Inc., for titanium and titanium-based alloys; Carpenter Technology Corporation for legacy nickel-based alloys and superalloys and specialty steel alloys; and Aubert & Duval for precision forgings.

Advanced Alloys & Solutions Segment

Our AA&S segment produces nickel-based alloys, titanium and titanium-based alloys, and specialty alloys in a variety of forms, including plate and sheet products. The major end markets for our flat rolled products are aerospace & defense, specialty and conventional energy, automotive, medical and electronics markets. The operations in this segment include our Specialty Rolled Products and Specialty Alloys & Components businesses in addition to our Shanghai STAL Precision Stainless Steel Company Limited (STAL) PRS joint venture in China, in which we hold a 60% interest.

Nickel-based alloys, titanium, and stainless sheet products are used in a wide variety of industrial and consumer applications. In fiscal year 2025, approximately 50% of our stainless sheet products by volume were sold to independent service centers, which have slitting, cutting or other processing facilities, with the remainder sold directly to end-use customers.

Nickel-based alloy, titanium, and specialty alloy plate products are primarily used in aerospace & defense, and corrosion and industrial markets. In fiscal year 2025, approximately 40% of our plate products by volume were sold to independent service centers, with the remainder sold directly to end-use customers.

Principal competitors for nickel-based alloys, superalloys, and specialty alloys produced by AA&S include Haynes International and VDM Metals GmbH, a subsidiary of Acerinox S.A.

Raw Materials and Supplies

Substantially all raw materials and supplies required in the manufacture of our products are available from more than one supplier, and the sources and availability of raw materials essential to our businesses are currently adequate. The principal raw materials we use in the production of our specialty materials are scrap (including iron-, nickel-, chromium-, titanium-, and molybdenum-bearing scrap), nickel, titanium sponge, zirconium sand and sponge, ferrochromium, ferrosilicon, molybdenum and molybdenum alloys, manganese and manganese alloys, cobalt, niobium, vanadium, hafnium and other alloying materials. While we enter into raw materials futures contracts from time to time to hedge exposure to price fluctuations, such as for nickel,

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we cannot be certain that our hedge position adequately reduces exposure. We believe that we have adequate controls to monitor these contracts, but we may not be able to accurately assess exposure to price volatility in the markets for critical raw materials.

We source our raw materials through a variety of producers located throughout the world, including the United States (U.S.). The following is a summary of the primary source countries of raw materials that play an important role in our products:

•Nickel: Canada, Norway, Japan, Finland, and South Africa.

•Zirconium: U.S. and China.

•Hafnium: U.S. and China.

•Cobalt: Norway and Japan.

•Chromium: the United Kingdom (U.K.), South Africa, Germany and Turkey.

•Niobium: Brazil.

•Molybdenum: U.S., Brazil, and China.

•Titanium sponge: Japan, Kazakhstan, Saudi Arabia, and China

Some raw materials, such as nickel, titanium sponge, cobalt, and ferrochromium, are mostly available from foreign sources in countries that may be subject to unstable political and economic conditions, which could disrupt supplies or affect the price of these materials. Further, changes in global trade policies could materially impact the total cost of imported materials.

Certain key supplies used in melting and other processing operations, such as graphite electrodes and industrial gases including helium and argon, are from time-to-time limited in availability and may be subject to significant price inflation. We enter into long-term supply contracts where possible to ensure an adequate supply of these products. However, overall industry shortages may impact our operations and scheduling.

Export Sales and Foreign Operations

International sales represent approximately 42% of our total annual sales, with direct export sales by our U.S.-based operations to customers in foreign countries accounting for approximately 34% of our total sales. Our overseas sales, marketing and distribution efforts are aided by our international marketing team or by independent representatives throughout the world. Changes in global trade policies may negatively impact our international sales if export or import tariffs increase the cost of our products.

Our HPMC segment has manufacturing capabilities for precision forging and machining in Poland, primarily serving the aerospace, construction & mining, and transportation markets. Within our AA&S segment, our Asian joint venture makes PRS products, which enables us to offer these products more effectively to markets in China and other Asian countries.

Backlog, Seasonality and Cyclicality

Our backlog of confirmed orders was approximately $3.7 billion at December 28, 2025 and $3.9 billion at December 29, 2024. We expect that approximately 70% of confirmed orders on hand at December 28, 2025 will be filled during fiscal year 2026. Our HPMC segment’s backlog of confirmed orders was approximately $3.1 billion at December 28, 2025 and $3.3 billion at December 29, 2024. We expect that approximately 70% of the confirmed orders on hand at December 28, 2025 for this segment will be filled during fiscal year 2026. Our AA&S segment’s backlog of confirmed orders was approximately $0.6 billion at December 28, 2025 and December 29, 2024. We expect that approximately 90% the confirmed orders on hand at December 28, 2025 for this segment will be filled during fiscal year 2026.

Demand for our products is cyclical over longer periods because specialty materials customers generally operate in cyclical industries and are subject to changes in general economic conditions and other factors both external and internal to those industries. Historically, we have experienced modest seasonal weakness in the third quarter of each fiscal year. This is mostly due to planned outages by certain European customers, particularly those in the aerospace supply chain, that are typically scheduled for the late summer months each year.

Research, Development and Technical Services

We believe that our research and development capabilities give ATI a competitive advantage in developing new products and manufacturing processes that contribute to the long-term profitable growth potential of our businesses. We conduct research and development at our various operating locations both for ourselves and, on a limited basis, for customers on a contract basis. Research and development expenditures for the fiscal years ended December 28, 2025, December 29, 2024, and December 31, 2023 included the following:

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Fiscal Year Ended

Company-Funded:

High Performance Materials & Components $ 10.1 $ 10.4 $ 9.6

Advanced Alloys & Solutions 10.3 8.4 10.2

Customer-Funded:

High Performance Materials & Components 1.9 2.5 1.4

Total Research and Development $ 23.2 $ 22.1 $ 22.1

Our research, development and technical service activities are closely interrelated and directed toward development of new products, improvement of existing products, quality assurance, development of new manufacturing methods, improvement of existing manufacturing methods, and reducing our manufacturing costs.

We own hundreds of U.S. patents, many of which are also filed under the patent laws of other nations. Although these patents, as well as our numerous trademarks, technical information, license agreements, and other intellectual property, have been and are expected to be of value, we believe that the loss of any single such item or technically related group of such items would not materially affect the conduct of our business.

Environmental, Health and Safety Matters

We are subject to various domestic and international environmental laws and regulations that govern the discharge of pollutants and disposal of wastes, and which may require that we investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. We could incur substantial cleanup costs, fines, civil or criminal sanctions, third party property damage or personal injury claims as a result of violations or liabilities under these laws or non-compliance with environmental permits required at our facilities. We are currently involved in the investigation and remediation of a number of our current and former sites as well as third party sites.

We consider environmental compliance to be an integral part of our operations. We have a comprehensive environmental management and reporting program that focuses on compliance with applicable federal, state, regional and local environmental laws and regulations. Each operating company has an environmental management system that includes mechanisms for regularly evaluating environmental compliance and managing changes in business operations while assessing environmental impact.

Safety is one of our core values. We strive for a zero injury culture committed to the safety of our people, our products, and the communities in which we operate. Nearly all of our domestic employees are working in an ATI facility that has achieved its ISO 45001 certification.

Human Capital Management

We believe that our people and culture are a competitive differentiator. We attract, develop, and retain purpose and performance-driven leaders. Those leaders build teams with diverse, empowered and fulfilled employees who want to stay and grow with the company. As of December 28, 2025, we employed approximately 7,600 active employees, 15% of whom are located outside the U.S. across 15 countries.

Our Culture: At the center of our commitment to excellence are our values, which drive how we succeed: Accountability, Integrity, Innovation, Safety & Sustainability, and Teamwork & Respect.

We continuously strive to cultivate and support a highly engaged and productive workforce. We actively seek opportunities for listening and communication by our CEO and other senior executive leaders with our employees. Periodically, we conduct confidential company-wide engagement surveys that offer our employees the ability to provide feedback, which supports employee engagement and our overall human capital strategy.

Our long tradition of innovation and operational excellence demands the contributions of leaders and team members with a wide array of characteristics, backgrounds, experiences, knowledge, and skills.We believe our business success is intricately tied to cultivating a culture in which all members of our workforce are included and empowered to do their best work.

Governance: The Compensation and Leadership Development Committee of our Board oversees the Company’s human capital management policies and procedures, including its workforce and professional development programs, and is responsible for establishing and administering the policies governing annual compensation and long-term compensation to ensure the policies are designed to align compensation with our overall business strategy and performance to link to the interests of our stockholders.

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Our Code of Conduct establishes the baseline requirements of our integrity and compliance program and promotes an environment where everyone is treated ethically and with respect. It outlines our pledge to recognize the dignity of each individual, respect each employee, provide compensation and benefits that are competitive, promote self-development through training, and value diversity of perspectives and ideas. Employees complete Business Conduct and Ethics training and, where permitted by law, are asked to certify each year that they will comply with the Code.

Talent Acquisition: Our performance and development process is integrated in the ATI business strategy, and is a key component to recruiting, hiring, and developing top-performing talent. We believe in providing an assessment and interviewing process that encourages people from all backgrounds to consider ATI. We partner with top academic institutions that have programs relevant to our business, external professional organizations, trade schools and high schools to identify materials science, STEM and other relevant expertise.

Learning and Development: Developing talent and leaders at all levels of the organization is critical to our long-term success. We have leadership and management development programs as well as broad learning opportunities for our employees to support their career growth and advance their skills. We focus on growing top talent across the enterprise and enhancing Front Line Leader development. Additionally, we maintain a formal talent review process to work in connection with performance management for systematic career development and succession planning at both the individual employee and organizational levels.

Compensation and Benefits:We provide market-based competitive compensation through our salary, annual incentive and long-term incentive programs and robust benefits packages that promote the well-being of our employees across all aspects of their lives.Eligible employees are compensated for their contributions to achievement of our goals with both short-term cash incentives and long-term equity-based incentives. We believe the structure of our compensation packages provides the appropriate incentives to attract, retain, and motivate our employees.

Our well-being focus addresses physical, mental, financial, and individual needs, providing benefits and resources to help employees and their families be their best, both personally and professionally. We have implemented several campaigns to promote well-being and help provide visibility to resources and available benefits. We offer Employee Assistance Programs with therapy sessions to employees and family members, comprehensive mental health benefits to those enrolled in the U.S. medical plan, virtual mental health options and navigation tools to improve access and speed of care, and preventive/mental health resilience programs.

Labor Relations and Collective Bargaining: Approximately 35% of our workforce is covered by various collective bargaining agreements (CBAs), predominantly with the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied & Industrial Service Workers International Union (USW). On April 22, 2025, we reached agreements with the USW for new CBAs that cover approximately 1,100 USW represented full-time employees within our AA&S operations for a six-year term that extends through February 28, 2031.

Available Information

Our Internet website address is www.atimaterials.com. Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as well as proxy and information statements and other information that we file, are available free of charge through our Internet website as soon as reasonably practicable after we electronically file such material with, or furnish such material to, the U.S. Securities and Exchange Commission (“SEC”). Our Internet website and the content contained therein or connected thereto are not intended to be incorporated into this Annual Report on Form 10-K. The SEC maintains an Internet website at www.sec.gov, which also contains reports, proxy and information statements and other information that we file electronically with the SEC. We routinely post important information on our website, www.atimaterials.com, in the “Investors” section. We also may use our website as a means of disclosing material, non-public information and for complying with our disclosure obligations under Regulation FD. Accordingly, investors should monitor the Investors section of our website, in addition to following our press releases, SEC filings, public conference calls, presentations and webcasts. The information contained on, or that may be accessed through, our website is not incorporated by reference into, and is not a part of, this document.

Item 1A. Risk Factors

There are inherent risks and uncertainties associated with our business that could adversely affect our operating performance and financial condition. Set forth below are descriptions of those risks and uncertainties that we currently believe to be material, but the risks and uncertainties described are not the only risks and uncertainties that could affect our business. See the discussion under “Forward-Looking Statements” in Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations, in this Annual Report on Form 10-K.

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RISKS RELATED TO CYCLICAL NATURE OF OUR BUSINESS

Cyclical Demand for Products. The cyclical nature of the industries in which our customers operate causes demand for our products to fluctuate, creating potential uncertainty regarding future profitability. Various changes in general economic conditions may affect the industries in which our customers operate. These changes could include decreases in the rate of consumption or use of our customers’ products due to economic downturns. Other factors that may cause fluctuation in our customers’ positions are changes in market demand, lower overall pricing due to domestic and international overcapacity, currency fluctuations, lower priced imports and increases in use or decreases in prices of substitute materials. As a result of these factors, our profitability has been and may in the future be subject to significant fluctuation.

Risks Associated with the Commercial Aerospace Industry. A significant portion of our sales represent products sold to customers in the commercial aerospace industry. Fulfilling contractual arrangements to provide various products to customers in this industry often involves meeting highly exacting performance requirements and product specifications, and our failure to meet those requirements and specifications on a timely and cost-efficient basis could have a material adverse effect on our results of operations, business and financial condition. The commercial aerospace industry has historically been cyclical due to factors both external and internal to the airline industry. These factors include general economic conditions, airline profitability, consumer demand for air travel, varying fuel and labor costs, changes in projected build rates, price competition, and international and domestic political conditions such as military conflict and the threat of terrorism. The length and degree of cyclical fluctuation are influenced by these factors and therefore are difficult to predict with certainty. Demand for our products is subject to these cyclical trends. Cyclical and event-driven downturns in the commercial aerospace industry have had, and may in the future have, an adverse effect on the prices at which we are able to sell our products, and our results of operations, business and financial condition could be materially adversely affected.

Risks Associated with Cyclicality in General Industrial Markets. Our exposure to general industrial markets is primarily in our AA&S segment, where we have sales to the oil and gas industry, automotive, food equipment & appliances and construction and mining markets. These markets tend to be highly cyclical and subject to volatility as a result of fluctuations in worldwide economic activity and associated demand, changes in applicable regulation, global geopolitical conditions and numerous other factors. Demand for our products, particularly within the AA&S segment, is subject to these trends, and in recent years, our business has at times been negatively impacted by depressed demand from general industrial markets. We expect that these end markets will remain highly cyclical. Future downturns in these markets could have an adverse effect on the prices at which we are able to sell our products, and our results of operations, business and financial condition could be materially adversely affected.

Risks Associated with Product Pricing. From time-to-time, reduced demand, intense competition, and excess manufacturing capacity have resulted in reduced prices, excluding raw material surcharges, for many of our products. These factors, recent inflationary trends for certain critical raw material costs, and potential international trade actions, as discussed below, have had and may have an adverse impact on our revenues, operating results, and financial condition.

We change prices on certain of our products from time-to-time. Our ability to implement price increases is dependent on market conditions, economic factors, raw material costs and availability, competitive factors, operating costs and other factors, some of which are beyond our control. As such, we may be unable to implement price increases to the degree or within the time frame necessary to fully mitigate the impact of inflationary trends, including those resulting from changes in trade policy, or at all, and the benefits of any price increases may be delayed due to long manufacturing lead times and the terms of existing contracts.

Risks Associated with Key Customers. We have long-term contracts with certain of our customers, some of which are subject to renewal, renegotiation, or re-pricing at periodic intervals or upon changes in competitive supply conditions. Our failure to successfully renew, renegotiate or favorably re-price such agreements, or a material deterioration in or termination of these or other key customer relationships, could result in a reduction or loss in customer purchase revenue. Loss of a key customer could negatively impact our business. Additionally, a significant downturn or deterioration in the markets we serve could cause key customers to change their business strategies or modify their business relationships with us, including to reduce the amount of our products they purchase or to switch to alternative suppliers, as a result of which our financial condition and results of operations may be adversely affected.

RISKS RELATED TO THE RAW MATERIALS AND SUPPLIES THAT WE USE

Dependence on Critical Raw Materials Subject to Price and Availability Fluctuations. We rely to a substantial extent on third parties to supply certain raw materials that are critical to the manufacture of our products. Purchase prices and availability of these critical items are subject to volatility, and in some cases, we have supply arrangements with only a limited number of suppliers for a given material. At any given time, we may be unable to obtain an adequate supply of these critical raw materials on a timely basis, on price and other terms acceptable to us, or at all. If suppliers increase the price of critical raw materials, we

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may not have alternative sources of supply. In addition, to the extent that we have quoted prices to customers and accepted customer orders for products prior to purchasing necessary raw materials, or have existing contracts, we may be unable to raise the price of products to cover all or any part of the increased cost of the raw materials. We source some of these materials from China, which has imposed, and may in the future continue to impose, export controls that could limit or significantly delay our access to such materials and could compel us to identify alternative sources, which we may not be able to do in a timely fashion or at all. The prices for many of the raw materials we use have been volatile during the past several years. Due to the long lead times required to manufacture many of our products, volatility in raw material prices exposes us to cash costs that may not be fully recovered through surcharge and index pricing mechanisms. Recently, due to inflationary trends, certain critical raw material costs, such as for nickel, hafnium, titanium sponge, cobalt, chromium, molybdenum, and scrap containing iron, nickel, titanium, chromium and molybdenum, have been volatile, and they may continue to be so in the future, including as a result of changes in international trade policy. While we have been able to mitigate some of the adverse impact of volatile raw material costs through various means, including the application of raw material surcharges or pricing indices to customers, rapid changes in raw material costs cause volatility in, and may adversely affect, our results of operations.

The manufacture of some of our products is a complex process and requires long lead times. As a result, we may experience delays or shortages in the supply of raw materials. In particular, we acquire certain important raw materials that we use to produce specialty materials, including nickel, zirconium, niobium, chromium, cobalt, vanadium and titanium sponge, from foreign sources. Some of these sources operate in countries that may be subject to unstable political and economic conditions. These or similar conditions may disrupt supplies or affect the prices of the materials that are necessary to our operations. If unable to obtain adequate and timely deliveries of required raw materials, we may be unable to timely manufacture sufficient quantities of products. This could cause us to lose sales, incur additional costs, delay new product introductions, or suffer harm to our reputation.

Dependence on Critical Supplies Subject to Price and Availability Fluctuations. We rely on third parties for certain supplies, such as graphite electrodes and industrial gases including helium and argon, that are critical to the manufacture of our products. Purchase prices and availability of these critical items are subject to volatility. At any given time, we may be unable to obtain an adequate supply of these critical supplies on a timely basis, on price and other terms acceptable to us, or at all. The manufacture of some of our products is a complex process and requires long lead times. If suppliers increase the price of these critical supplies, we may not have alternative sources of supply. As a result, we may experience delays or shortages of critical supplies. If unable to obtain adequate and timely deliveries of required supplies, we may be unable to timely manufacture sufficient quantities of products. This could cause us to lose sales, incur additional costs, delay new product introductions, or suffer harm to our reputation.

Availability of Energy Resources. We rely upon third parties for our supply of energy resources consumed in the manufacture of our products. The prices for and availability of electricity, natural gas, oil and other energy resources are subject to volatile market conditions. These market conditions often are affected by political and economic factors and by supply and demand trends that are beyond our control. Disruptions in the supply of energy resources could temporarily impair our ability to manufacture products for customers. Further, increases in energy costs, or changes in costs relative to energy costs paid by competitors, has in the past adversely affected our profitability and may continue to do so in the future. To the extent that these uncertainties cause suppliers and customers to be more cost sensitive, increased energy prices may have an adverse effect on our results of operations and financial condition.

The ongoing conflict between Russia and Ukraine may adversely affect our business and results of operations.

Since February 2022, Russia and Ukraine have been engaged in active armed conflict. The length, impact, and outcome of the ongoing conflict and its potential impact on our business is highly volatile and difficult to predict. It has and could continue to cause significant market and other disruptions, including significant volatility in commodity prices and supply of energy resources, instability in financial markets, supply chain interruptions, political and social instability, trade disputes or trade barriers, changes in consumer or purchaser preferences, and increases in cyberattacks and espionage.

Governments in the European Union, the U.S., the U.K. and other countries have enacted sanctions against Russia and Russian interests. These sanctions include controls on the export, re-export, and in-country transfer in Russia of certain goods, supplies, and technologies, and the imposition of restrictions on doing business with certain state-owned Russian customers and other investments and business activities in Russia. We terminated our Uniti, LLC joint venture with Russian-based VSMPO-AVISMA (Verkhnaya Salda Metallurgical Production Association - Berezniki Titanium-Magnesium Works), the purpose of which was to market and sell a range of commercially pure titanium products. However, conditions in Ukraine and/or existing or future sanctions may disrupt supplies or affect the prices of materials that are necessary to our operations. If unable to obtain adequate and timely deliveries of required raw materials, we may be unable to timely manufacture sufficient quantities of products. This could cause us to lose sales, incur additional costs, delay new product introductions, or suffer harm to our reputation.

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Further, the broader consequences of the current conflict between Russia and Ukraine may also have the effect of heightening many other risks disclosed in our public filings, any of which could materially and adversely affect our business and results of operations. Such risks include, but are not limited to, adverse effects on global macroeconomic conditions; increased volatility in the price and demand of oil, natural gas and other commodities, increased exposure to cyberattacks; disruptions in global supply chains; and exposure to foreign currency fluctuations and potential constraints or disruption in the capital markets and our sources of liquidity.

RISKS RELATED TO OUR WORKFORCE

Risks Associated with the Recruitment and Retention of Key Talent and the Sustainability of our Workforce.Our business and manufacturing processes are complex. We require highly skilled personnel with relevant industry and technical experience to effectively operate, and as such, depend on our ability to recruit, retain and motivate our employees. Shortages in skilled labor and other labor market pressures currently are resulting in greater competition for skilled labor and increased labor costs in some instances. If we fail to attract, develop, retain and motivate a sustainable workforce with the skills and in the locations we need to operate and grow our business, our operations could be adversely impacted.

In addition, the loss of key members of management and other personnel could negatively impact our business, and any unplanned turnover, or failure to develop adequate succession plans for key positions, could result in loss of technical or other expertise or institutional knowledge, delay or impede the execution of our strategic plans and priorities and, ultimately, negatively impact our business and results.

Labor Matters. We have approximately 7,600 active employees, of which approximately 15% are located outside the U.S. Approximately 35% of our workforce is covered by various CBAs, predominantly with the USW. At various times, our CBAs expire and are subject to renegotiation. Generally, CBAs that expire may be terminated after notice by the union. After termination, the union may authorize a strike. A labor dispute, which could lead to a strike, lockout, or other work stoppage by the employees covered by one or more of the collective bargaining agreements, could have a material adverse effect on production at one or more of our facilities and, depending upon the length of such dispute or work stoppage, on our operating results. Additionally, labor organizations may from time to time attempt to organize groups of additional employees who are not currently covered by any of the CBAs to which we are a party. The outcome of any such efforts may be influenced by many factors and is difficult to predict. There can be no assurance that we will succeed in obtaining CBAs to replace those that expire or in negotiating new CBAs on terms acceptable to us or at all.

RISKS RELATED TO INTELLECTUAL PROPERTY, INFORMATION TECHNOLOGY AND SECURITY

Risks Associated with our Intellectual Property. We own valuable intellectual property, including trade secrets, patents, trademarks and copyrights. Our intellectual property protects our investments in technological innovation, research and development, and plays an important role in maintaining our competitive position in the markets we serve. Despite efforts to secure our intellectual property, it may be infringed or misappropriated by our employees, our competitors or other third parties. The pursuit of remedies for infringement or misappropriation of intellectual property is expensive and uncertain. Additionally, our competitors may develop technologies of their own that are similar or superior to our proprietary technologies, or design around our patents, to lawfully avoid our intellectual property rights. A failure to sufficiently secure or successfully enforce our intellectual property rights could adversely affect our business and competitive position.

Risks Associated with Digital Technology. Information technology infrastructure is critical to supporting business objectives; failure of our information technology infrastructure to operate effectively could adversely affect our business. If a problem occurs that impairs this infrastructure, the resulting disruption could impede our ability to record or process orders, manufacture and ship in a timely manner, or otherwise carry on business in the normal course. Any such events could cause us to lose customers or revenue and could require us to incur significant remediation expense. As we integrate, implement and deploy new information technology processes and information infrastructure across our operations, we could experience disruptions in our business that could have an adverse effect on our business, financial condition, results of operations and cash flow.

Risks Associated with Cybersecurity Threats. Increased global information technology threats, vulnerabilities, and a rise in sophisticated and targeted international computer crime pose a risk to the security of our systems and networks and the confidentiality, availability and integrity of our data. We believe that ATI faces the threat of such cyberattacks due to the markets we serve, the products we manufacture, the locations of our operations, and global interest in our technology. Due to the evolving nature of cybersecurity threats, the scope and impact of any incident cannot be predicted. We continually work to strengthen our threat countermeasures, safeguard our systems and mitigate potential risks. Despite our efforts to fortify our cybersecurity and protect sensitive information and confidential and personal data, our facilities and systems, and those of our third-party service providers, may be vulnerable to security breaches. A significant security breach could lead to unanticipated disclosure, modification or destruction of proprietary and other key information, production downtimes, operational disruptions,

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the loss of customers, and remediation costs and other losses or liabilities, which in turn could adversely affect our reputation, competitiveness and results of operations.

RISK RELATED TO CLIMATE CHANGE AND OTHER ENVIRONMENTAL MATTERS

Risks Associated with Climate Change.

While the prospect of a lower-carbon economy presents a number of opportunities for our business, the physical impacts of climate change, regulatory efforts to transition to a lower-carbon economy in the regions in which we, our customers and our suppliers operate, and the focus and evolving views of our various stakeholders on climate change issues could create risks to our business.

Physical Risk. Climate related changes in prevailing weather patterns may impact, among other conditions, changes in sea levels and the propensity for flooding in coastal and other regions, long-term changes in precipitation patterns leading to flooding, drought or deterioration in water quality, and increases in the frequency and severity of significant storms and other weather events and related natural hazards, such as wildfire risk. Although we do not believe that our facilities are currently exposed to significant physical risk as a general matter, our operations have at times been, and could in the future be, impacted by adverse climate-related events, such as, for example, unanticipated periods of extreme cold or heat, acute flooding and wide-spread wildfires such as those experienced in certain regions in the U.S. and elsewhere in recent years. Events such as these could cause damage to critical facilities and equipment, result in significant operational disruption and have meaningfully adverse effects on our employees and the communities in which we operate. Additionally, even to the extent that significant weather events or changes in climate conditions do not directly impact our own facilities and/or operations, our business could be negatively impacted by events or more chronic climate conditions that disrupt or force longer-term changes in operations for our significant customers or suppliers, which could negatively impact the timing or overall volume of demand for our products or the cost and availability of critical raw materials, among other factors. Over time, widespread physical climate changes and risks could drive increases in other operational costs for our business, such as insurance costs.

Regulatory and Other Transition Risks. Worldwide focus on climate change has led to legislative and regulatory efforts to combat both potential causes and adverse impacts of climate change. New or more stringent laws and regulations related to greenhouse gas emissions, water usage and other climate change related concerns may adversely affect us, our suppliers and our customers. We have publicly disclosed efforts to reduce certain environmental impacts, including greenhouse gas (GHG) emissions of our operations, and provide for our compliance with applicable environmental regulations. Nevertheless, new and evolving laws and regulations could mandate different or more restrictive standards; increase operating costs; require (or cause customers to require that we make) capital investments to transition to low carbon technologies or purchase carbon credits; or otherwise adversely impact our ongoing operations. Our suppliers may face similar challenges and incur additional compliance costs that are passed on to us. These direct and indirect costs may adversely impact our results.

Market and Reputational Risks.Technology to support the transition to lower-carbon operations within the timeframe that could be required by future regulation or expected in the future by our customers may not be available at the scale necessary to support our operations in a timely or cost-effective manner or at all. It is possible that, over time, due to both regulatory action and/or changing customer and societal norms and expectations regarding the causes and importance of climate change issues, demand for products in one or more of our significant end markets could decline or, if we fail to keep pace with changing demand and technological advancement, shift in favor of products that we do not produce. If we fail to appropriately adapt to the expectations of our customers or other stakeholders, fail to achieve or properly report progress toward our environmental sustainability goals and targets or otherwise are perceived as failing to adequately address climate change concerns, the resulting negative perceptions could adversely affect our business, reputation and access to capital.

Risks Associated with Other Environmental Compliance Matters. We are subject to various domestic and international environmental laws and regulations that govern the discharge of pollutants and disposal of wastes, and may require that we investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. We could incur substantial cleanup costs, fines and civil or criminal sanctions, third party property damage or personal injury claims as a result of violations or liabilities under these laws or non-compliance with environmental permits required at our facilities. We are currently involved in the investigation and remediation of a number of our current and former sites as well as third party sites. With respect to proceedings brought under the federal Superfund laws, or similar state statutes, we have been identified as a potentially responsible party (PRP) at 40 of such sites, excluding those at which we believe we have no future liability. Our involvement is limited or de minimis at approximately 19 of these sites, and potential loss exposure with respect to 13 individual sites is not considered to be material. The potential loss exposure on the remaining eight sites could be material. We are a party to various cost-sharing arrangements with other PRPs at many of the sites. The terms of the cost-sharing arrangements are subject to non-disclosure agreements as confidential information. Nevertheless, the cost-sharing arrangements generally require all PRPs to post financial assurance of the performance of the obligations or to pre-pay into an

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escrow or trust account their share of anticipated site-related costs. In addition, the Federal government, through various agencies, is a party to several such arrangements.

From time-to-time, we are a party to lawsuits and other proceedings involving alleged violations of, or liabilities arising from, environmental laws. When our liability is probable and we can reasonably estimate our costs, we record environmental liabilities in our financial statements. In many cases, we are not able to determine whether we are liable or if liability is probable or to reasonably estimate the potential loss or range of loss associated with an alleged claim. Estimates of our liability remain subject to additional uncertainties, including the nature and extent of site contamination, available remediation alternatives, the extent of corrective actions that may be required, and the participation number and financial condition of other PRPs, as well as the extent of their responsibility for the remediation. We intend to adjust our accruals to reflect new information as appropriate. Future adjustments could have a material adverse effect on our results of operations in a given period, but we cannot reliably predict the amounts of such future adjustments. At December 28, 2025, our reserves for environmental matters totaled approximately $15 million. Based on currently available information, we do not believe that there is a reasonable possibility that a loss exceeding the amount already accrued for any of the sites with which we are currently associated (either individually or in the aggregate) will be an amount that would be material to a decision to buy or sell our securities. Future developments, administrative actions or liabilities relating to environmental matters, however, could have a material adverse effect on our financial condition or results of operations.

OTHER OPERATIONAL AND STRATEGIC RISKS

Risks Associated with Disruptions to our Manufacturing Processes. The manufacture of many of our products is a highly exacting and complex process.If we encounter disruptions to our manufacturing processes due to equipment malfunction, failure to follow specific protocols, specifications and procedures, supply chain interruptions, natural disasters, geopolitical volatility, health pandemics, cybersecurity breaches, labor unrest, or otherwise, it could have an adverse impact on our ability to fulfill orders or on product quality or performance which could result in significant costs to and liability for us that could have a material adverse effect on our business, financial condition or results of operations, as well as negative publicity and damage to our reputation, which could adversely impact product demand and customer relationships.Additionally, our operations depend on the continued and efficient functioning of our facilities, including critical equipment.If our operations, particularly one of our manufacturing facilities, were to be materially disrupted for any reason, we may be unable to effectively meet our obligations to or demand from our customers, which could adversely affect our financial performance.

Risks Associated with Export Sales and International Trade Matters. We believe that export sales will continue to account for a significant percentage of our future revenues. We also import certain raw materials that are important to our business, including nickel, zirconium, niobium, chromium, hafnium, cobalt, vanadium and titanium sponge, among others. Risks associated with such international trade include, among others: political and economic instability, including weak conditions in the world’s economies; accounts receivable collection; export controls; trade sanctions; changes in legal and regulatory requirements; policy changes affecting the markets for our products; changes in tax laws, including taxes on repatriation of foreign earnings; and exchange rate fluctuations (which may affect sales to international customers and the value of profits earned on export sales when converted into dollars). Any of these factors could materially adversely affect our results for the period in which they occur. We source some materials from China, which has and may in the future continue to impose export controls that could limit or significantly delay our access to such materials and could compel us to identify alternative sources, which we may not be able to do in a timely fashion or at all.

Additionally, global trade policy may, at times, be volatile and unpredictable, and changes in international trade duties and other aspects of international trade policy, both in the U.S. and abroad, could materially impact our business. Tariffs, or other changes in U.S. trade policy, have resulted in and may continue to trigger, retaliatory actions by affected countries. At times, certain foreign governments have instituted or considered imposing trade sanctions on certain U.S. goods, or taking action to deny U.S. companies access to critical raw materials in response to U.S. trade actions, and these or other foreign governments could continue or expand upon these actions in the future. A “trade war” of this nature or other governmental action related to tariffs or international trade agreements or policies has the potential to adversely impact demand for our products, our costs, customers, suppliers and/or the U.S. economy or certain sectors thereof and, thus, to adversely impact our businesses.

Risks Associated with Strategic Capital Projects and Maintenance Activities. From time to time, we undertake strategic capital projects in order to enhance, expand and/or upgrade our facilities and operational capabilities. Our ability to achieve the anticipated increased revenues or otherwise realize acceptable returns on these investments or other strategic capital projects that we may undertake is subject to a number of risks, many of which are beyond our control, including a variety of market, operational, permitting, and labor-related factors. In addition, the cost to implement any given strategic capital project ultimately may prove to be greater than originally anticipated. If we are not able to achieve the anticipated results from the implementation of any of our strategic capital projects, or if we incur unanticipated implementation costs or delays, our results of operations and financial position may be materially adversely affected. Additionally, we periodically undertake maintenance activities, routine or otherwise, involving facilities and pieces of equipment that are key to our operations, and it is possible that

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unanticipated maintenance needs, or unanticipated circumstances arising in connection with planned maintenance activities could result in equipment outages that are longer, or costs that exceed, those originally anticipated. Significant repair delays or unanticipated costs associated with these activities could have a negative impact on our results of operations and financial condition.

Risks Associated with Current or Future Litigation and Claims. A number of lawsuits, claims and proceedings have been or may be asserted against us relating to the conduct of our currently and formerly owned businesses, including those pertaining to product liability, patent infringement, commercial disputes, government contracting, employment matters, employee and retiree benefits, taxes, environmental matters, personal injury and health and safety and occupational disease, and stockholder and corporate governance matters.Due to the uncertainties of litigation, we can give no assurance that we will prevail on all claims made against us in the lawsuits that we currently face or that additional claims will not be made against us in the future.While the outcome of litigation cannot be predicted with certainty, and some of these lawsuits, claims or proceedings may be determined adversely to us, we do not believe that the disposition of any such pending matters is likely to have a material adverse effect on our financial condition or liquidity. However, the resolution in any reporting period of one or more of these matters could have a material adverse effect on our results of operations for that period.Also, we can give no assurance that any other claims brought in the future will not have a material effect on our financial condition, liquidity or results of operations.

In August 2024, the Company received notice that it and certain of its affiliates are parties to two lawsuits, filed in federal district court for the Western District of Pennsylvania, that assert various claims associated with the Company’s October 2023 purchase of group annuity contracts to transfer a portion of its U.S. qualified defined benefit pension plan obligations to Athene Annuity and Life Company and Athene Annuity & Life Assurance of New York.These two lawsuits were consolidated in late 2024, and in January 2025, we filed a motion to dismiss the consolidated claims.Following an August 2025 hearing on the motion to dismiss, the magistrate judge covering the Motion issued a report recommending that all of the plaintiffs’ claims be dismissed for lack of standing.The recommendation remains subject to review and disposition by the presiding judge.We intend to vigorously defend against these claims, but given the preliminary nature of these matters, cannot predict their outcome or estimate any range of reasonably possible loss at this time.

Risks Associated with Insurance Coverage. We have maintained various forms of insurance, including insurance covering claims related to our properties and risks associated with our operations. Our existing property and liability insurance coverages contain exclusions and limitations on coverage. From time-to-time, in connection with renewals of insurance, we have experienced additional exclusions and limitations on coverage, larger self-insured retentions and deductibles, and significantly higher premiums. As a result, in the future, our insurance coverage may not cover claims to the extent that it has in the past and the costs that we incur to procure insurance may increase significantly, either of which could have an adverse effect on our results of operations.

Risks Associated with Acquisition and Disposition Strategies. We intend to continue to strategically position our businesses to improve our ability to compete. Strategies we employ to accomplish this may include seeking new or expanding existing specialty market niches for our products, expanding our global presence, acquiring businesses complementary to existing strengths, and continually evaluating the performance and strategic fit of our existing business units and their components, as a result of which we may choose to dispose of any such business or related assets. From time-to-time, management holds discussions with management of other companies to explore acquisitions, joint ventures, and other business combination opportunities, as well as possible asset acquisitions or dispositions. As a result, the relative makeup of the businesses comprising our Company is subject to change. Acquisitions, joint ventures, and other business combinations involve various inherent risks, such as: the relative accuracy of our assessment of the value, strengths, weaknesses, contingent and other liabilities and potential profitability of acquisition or other transaction candidates; the potential loss of key personnel of an acquired business; unanticipated conditions or events that impact our ability to achieve identified financial and operating synergies, growth or other benefits anticipated to result from an acquisition or other transaction; and unanticipated changes in business and economic conditions. The relative success of any business or asset acquisitions and other similar transactions, particularly any cross-border transaction, also could be negatively affected by export controls, exchange rate fluctuations, domestic and foreign trade policy and other geopolitical conditions, changes in tax laws and deterioration in domestic and foreign economic conditions.

Risks Associated with Government Contracts. Some of our operating units perform contractual work directly or indirectly for the U.S. Government, which requires compliance with laws and regulations relating to the performance of Government contracts. Various claims (whether based on U.S. Government or Company audits and investigations or otherwise) could be asserted against us related to our U.S. Government contract work. Depending on the circumstances and the outcome, such proceedings could result in fines, penalties, compensatory and treble damages or the cancellation or suspension of payments

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under one or more U.S. Government contracts. Under government regulations, a company, or one or more of its operating divisions or units, can also be suspended or debarred from government contracts based on the results of investigations.

Risks Related to Wide-Spread Public Health Crises. The COVID-19 pandemic, including governmental and other actions taken or restrictions imposed to contain its spread and impact, subjected our operations, financial performance and financial condition to a number of risks. In general, our facilities continued to operate throughout the pandemic with federal and state government approvals because our facilities were deemed essential and critical. However, we experienced, and may again in the context of future similar events experience, the temporary shut-down of facilities. The significant macroeconomic impact of the COVID-19 pandemic and the measures designed to contain its spread also negatively impacted several of the Company’s most significant end markets, and our sales to customers in those markets. Any future similar event could impact our business, results of operations, financial condition and/or cash flows in similar respects, but the ultimate breadth and duration of any such future event and its impacts on our business are difficult to predict.

Risks Associated with Political and Social Turmoil. The war on terrorism, as well as global political and social turmoil, generally, could put pressure on economic conditions in the U.S. and worldwide. These political, social and economic conditions could make it difficult for us, our suppliers, and our customers to forecast accurately and plan future business activities, and could adversely affect the financial condition of our suppliers and customers and affect customer decisions as to the amount and timing of purchases from us. As a result, our business, financial condition and results of operations could be materially adversely affected.

RISKS ASSOCIATED WITH OUR INDEBTEDNESS; OTHER FINANCIAL AND FINANCIAL ACCOUNTING RISKS

Risks Associated with Indebtedness. Our substantial indebtedness could adversely affect our business, financial condition or results of operations and prevent us from fulfilling our obligations under our outstanding indebtedness. As of December 28, 2025, our total consolidated indebtedness was approximately $1.7 billion. We also had the ability to borrow approximately $569 million under our Asset Based Lending (ABL) credit facility, and up to $100 million of availability under the Delayed-Draw Term Loan as of December 28, 2025. This substantial level of indebtedness increases the risk that we may be unable to generate enough cash to pay amounts due in respect of our indebtedness. Our substantial indebtedness could have important consequences to our stockholders and significant effects on our business. For example, it could:

•make it more difficult for us to satisfy our obligations with respect to our outstanding indebtedness;

•increase our vulnerability to general adverse economic and industry conditions;

•require us to dedicate a substantial portion of our cash flow from operations to payments on our indebtedness, thereby reducing the availability of our cash flow to fund working capital, capital expenditures, our strategic growth initiatives and development efforts and other general corporate purposes;

•limit our flexibility in planning for, or reacting to, changes in our business and the industry in which we operate;

•restrict us from taking advantage of business opportunities;

•place us at a competitive disadvantage compared to our competitors that have less indebtedness; and

•limit our ability to borrow additional funds for working capital, capital expenditures, acquisitions, debt service requirements, execution of our business strategy or other general corporate purposes.

A portion of our indebtedness, including amounts outstanding currently or in the future under our ABL, bear interest at variable rates and, accordingly, subject our business to risk, particularly in a rising interest rate environment.In addition, the agreements that govern our current indebtedness contain, and the agreements that may govern any future indebtedness that we may incur may contain, financial and other restrictive covenants that could limit our ability to engage in activities that may be in our long-term best interests. Our failure to comply with those covenants could result in an event of default that, if not cured or waived, could result in the acceleration of all of our debt.

Risks Associated with Retirement Benefits. On October 17, 2023, we purchased group annuity contacts from an insurer covering approximately 85% of our U.S. qualified defined benefit plan obligations. Under these contracts, we transferred the pension obligations and associated assets for the significant majority of our remaining plan participants to the selected insurance company. Using our long-term weighted average expected return on pension plan assets and other actuarial assumptions, we expect to have approximately $40 million of minimum cash funding requirements to the defined benefit pension plan over the next ten years. Minimum cash funding requirements are not expected to be significant in any individual year. However, these estimates are based on various assumptions and are subject to significant uncertainty, including with respect to the performance of our pension trust assets, and our expectations therefore could prove to be inaccurate. Significantly lower than expected returns on our pension assets could result in otherwise unanticipated pension contribution obligations in the future. Depending

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on the timing and amount, a requirement that we fund the U.S. qualified defined benefit pension plan could have a material adverse effect on our results of operations and financial condition.

Risks Associated with Goodwill or Long-Lived Asset Impairments. We have various long-lived assets that are subject to impairment testing. We review the recoverability of goodwill annually, or more frequently whenever significant events or changes in circumstances indicate that the recorded goodwill of a reporting unit may be below that reporting unit’s fair value. Our businesses operate in highly cyclical industries, such as commercial aerospace, and as such, our estimates of future cash flows, market demand, the cost of capital, and forecasted growth rates and other factors may fluctuate, which may lead to changes in estimated fair value and, therefore, impairment charges in future periods. For the fiscal year 2025 annual goodwill impairment evaluation, both of our reporting units with goodwill had fair values that were in excess of carrying value. Additionally, we have a significant amount of property, plant and equipment and acquired intangible assets that may be subject to impairment testing, depending on factors such as market conditions, the demand for our products, and facility utilization levels. Any determination requiring the impairment of a significant portion of goodwill or other long-lived assets has had, and may in the future have, a negative impact on our financial condition and results of operations.

Risks Associated with Internal Controls Over Financial Reporting. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Risks Associated with Our Guidance and Other Targets and Expectations. From time to time, we may announce earnings guidance and other future targets or goals for our business. Such information, which consists of forward-looking statements, is based on our then current expectations, estimates, forecasts and projections about the operating environment, economies and markets in which we operate. Future targets and goals reflect our beliefs and assumptions and our perception of historical trends, then current conditions and expected future developments, as well as other factors appropriate in the circumstances. As such, while sometime presented with numerical specificity, earnings guidance and other statements regarding our future targets and goals are inherently speculative in nature and subject to significant business, economic, competitive and other uncertainties and contingencies regarding future events, including the risks discussed herein. Our actual results can, and likely will, be different, and those differences could be material. There can be no assurance that any targets or goals established by us will be accomplished at the levels or by the dates targeted, if at all. Failure to achieve our targets or goals may have a material adverse effect on our business, financial condition, results of operations or the market price of our securities.

Item 1B. Unresolved Staff Comments

None.

Item 1C. Cybersecurity

The Company and its Board recognize the critical significance that cybersecurity has to our operations and the need to continually assess cybersecurity risk and evolve our response in the face of a rapidly and ever-changing environment. We face a range of increasing and evolving cybersecurity threats common to industrial operations and other enterprises, which continue to grow in frequency and scope. See Item 1A, Risk Factors, “Cybersecurity Threats.”

The programs and procedures we have implemented to mitigate our exposure to these threats focus on preventing cybersecurity incidents, preserving the confidentiality, security and availability of the information that we generate or collect and store, and effectively responding to cybersecurity incidents if they occur.

Our Comprehensive Program

We take a comprehensive, standards-driven approach to our cybersecurity through an enterprise-wide cybersecurity program aligned with the National Institute on Standards and Technology’s Cybersecurity Framework. Our program includes an extensive set of systems, network and application-level controls that protect our corporate data and systems. Our Chief Digital and Information Officer (“CDIO”) and our Chief Information Security Officer (“CISO”), each of whom have extensive cybersecurity training and expertise and more than 25 years and 19 years of information technology and cybersecurity experience, respectively, hold primary responsibility within management for assessing, monitoring and managing our cybersecurity risks and program. They are supported by a dedicated, enterprise-wide cybersecurity team that, with the assistance of third-party providers, monitors our program and controls, as well as available cybersecurity intelligence, on a continuous basis to ensure that, as an organization, we are informed of emerging risks, identify specific threats and potential incidents, and promptly escalate the evaluation and management of identified incidents as appropriate. Components of our comprehensive program include, among others:

•Technical Safeguards. We deploy technical safeguards that are designed to protect the Company’s information systems from cybersecurity threats, including firewalls, intrusion prevention and detection systems, anti-malware

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functionality and access controls, which are evaluated through vulnerability assessments and cybersecurity threat intelligence.

•Third-Party Risk Management. We maintain a risk-based approach to identifying and overseeing cybersecurity risks presented by third parties.

•Program Assessments. We engage in regular assessments and testing of our policies and procedures, including efforts such as audits and similar assessments, tabletop exercises, threat modeling, vulnerability testing and other procedures focused on evaluating program effectiveness. Additionally, we periodically engage third parties to perform assessments of our cybersecurity measures, including information security maturity assessments and independent reviews of our information security control environment and operating effectiveness.

•Education and Awareness. We conduct a regular program of enterprise-wide communication and training regarding cybersecurity threats and the policies and procedures we have implemented in response. These programs are designed to elevate threat awareness within the Company and equip our employees with the knowledge and access to resources that they need to appropriately respond to and address the cybersecurity risks that we face.

•Incident Response and Recovery. We maintain extensive incident response and recovery plans and procedures that provide a documented framework for handling high severity security incidents. These plans ensure the appropriate escalation, evaluation, management and reporting of cybersecurity incidents in a prompt and appropriately cross-functional manner, facilitating coordination across multiple parts of the Company, and are the subject of regular table- top breach simulations and other exercises and evaluations.

•Insurance Coverage. We maintain a cybersecurity risk insurance policy to protect the Company against computer-related incidents and losses.

We have not experienced any material operational or financial impacts as a result of any cybersecurity incident or the cybersecurity risks that we face. At this time, while the threat of a cybersecurity incident is always present, we view our comprehensive mitigation strategies and procedures as appropriately calibrated safeguards against any material impact to our results of operation and financial condition as a result of a cybersecurity incident and believe that we are prepared to appropriately mitigate and respond to such an incident, should it occur.

Governance

Our Board is actively engaged in the oversight of our digital technology risk management and cybersecurity programs. As part of its program of regular oversight, the Audit and Risk Committee oversees ATI’s digital technology and cybersecurity risk.The regular review and assessment of the Company’s cybersecurity program and related policies, standards, processes and practices is a fully integrated component of the Company’s overall enterprise risk management program, and at least quarterly as a key component of each regularly scheduled meeting, the Committee receives regular reports from our CDIO on the Company’s cybersecurity risk profile, the functioning of its cybersecurity program, including with reference to key performance indicators and other specific, quantitative measures, and other digital technology risks.

Item 2. Properties

Our principal domestic facilities for the HPMC segment include melting operations and production facilities that perform processing and finishing operations, which are all substantially owned. Domestic melting operations are located in Monroe and Bakers, NC, and Richland, WA (vacuum induction melting, vacuum arc re-melt, electro-slag re-melt, plasma melting, electron beam melting). Production of high performance materials, most of which are in long product form, takes place at our domestic facilities in Monroe and Bakers, NC, Richburg, SC, and Oakdale, PA. Our production of highly engineered forgings and machined components takes place at facilities in Cudahy, Appleton and Coon Valley, WI, and Irvine, CA. In addition, we lease a facility in Margate, Florida to perform metal alloy-based additive manufacturing for the aerospace & defense industries.

Within the AA&S segment, our production of zirconium, hafnium, niobium and related specialty alloys takes place at facilities located in Millersburg, OR and Huntsville, AL. Nickel melting operations are located in Lockport, NY (vacuum induction melting, vacuum arc re-melt, and electro-slag re-melt), and titanium melting operations are located in Albany, OR (vacuum arc re-melt). Our principal AA&S locations for melting flat-rolled specialty materials are located in Brackenridge and Latrobe, PA. Hot-rolling is performed at our domestic facilities in Brackenridge and Washington, PA. Finishing of our flat-rolled products takes place at our domestic facilities located in Vandergrift, WA, Rochester, Monaca, and Zelienople, PA, and Pageland, SC. Substantially all of these properties are owned.

We lease facilities, primarily sales and administrative offices, in a number of foreign countries, including France, Germany, the U.K., Poland, Mexico, and the People’s Republic of China. We also own highly engineered forging and machining operations in Stalowa Wola, Poland. Through our STAL joint venture, we operate facilities for finishing PRS products in the Xin-Zhuang Industrial Zone, Shanghai, China.

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Our corporate headquarters in Dallas, TX and enterprise resource center in Pittsburgh, PA are leased.

Although our facilities vary in terms of age and condition, we believe that they have been well maintained and are in sufficient condition for us to carry on our activities. See Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations” for further discussion of these impacts.

Item 3. Legal Proceedings

From time to time, we become involved in various lawsuits, claims and proceedings relating to the conduct of our current and formerly owned businesses, including those pertaining to product liability, environmental, health and safety matters and occupational disease (including as each relates to alleged asbestos exposure), as well as patent infringement, commercial, government contracting, construction, employment, employee and retiree benefits, taxes, environmental, and stockholder and corporate governance matters.While we cannot predict the outcome of any lawsuit, claim or proceeding, our management believes that the disposition of any pending matters is not likely to have a material adverse effect on our financial condition or liquidity.The resolution in any reporting period of one or more of these matters, including those described above, however, could have a material adverse effect on our results of operations for that period.

In August 2024, the Company received notice that it and certain of its affiliates are parties to two lawsuits captioned (1) William L. Schoen, Mary J. Nesbit, Robin L. Rosewicz, George E. Poole and James E. Swartz, Jr., individually and as representatives of a class of participants and beneficiaries of the Allegheny Technologies Incorporated Pension Plan v. ATI Inc., The Allegheny Technologies Incorporated Pension Plan Administrative Committee, State Street Global Advisors Trust Co., and John Does 1-5 (Case No. 2:24-cv-01109) and (2) John Souza and Karen Souza, individually and as representatives on behalf of a class of similarly situated persons v. ATI Inc. and State Street Global Advisors Trust Co. (Case No. 2:24-cv-01214), both of which are filed in federal district court for the Western District of Pennsylvania. These lawsuits, which were consolidated in late 2024, assert various claims associated with the Company’s October 2023 purchase of group annuity contracts to transfer a portion of its U.S. qualified defined benefit pension plan obligations to Athene Annuity and Life Company and Athene Annuity & Life Assurance of New York. We filed a Motion to Dismiss the consolidated claims in January 2025. Following an August 2025 hearing on the Motion to Dismiss, the magistrate judge covering the Motion issued a report recommending that all the plaintiffs’ claims be dismissed for lack of standing. The recommendation remains subject to review and disposition by the presiding judge. We dispute and intend to vigorously defend against these claims, but given the preliminary nature of these matters, cannot predict their outcome or estimate any range of reasonably possible loss at this time.

Information relating to legal proceedings is included in Note 21. Commitments and Contingencies of the Notes to Consolidated Financial Statements and incorporated herein by reference.

Item 4. Mine Safety Disclosures

Not applicable.

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PART II

Item 5. Market for the Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Common Stock Prices

Our common stock is traded on the New York Stock Exchange (symbol ATI). At January 30, 2026, there were 1,527 record holders of ATI Inc. common stock. Currently, we do not pay a dividend. The future payment of dividends and the amount of such dividends would depend upon matters deemed relevant by our Board of Directors, such as our results of operations, financial condition, cash requirements, prospects, any limitations imposed by law, credit agreements or senior securities, and other factors deemed appropriate. Further, our ABL credit facility restricts our ability to pay dividends in certain circumstances. For more information on the restrictions under our ABL credit facility, see Note 16 of Item 8. “Financial Statements and Supplementary Data.”

Sales of Equity Securities

Set forth below is information regarding our stock repurchases during the fourth quarter of fiscal year 2025, comprised of shares repurchased by ATI under the $700 million repurchase program authorized by our Board of Directors in September 2024 and shares repurchased by ATI from employees to satisfy employee-owed taxes on share-based compensation.

(a) Includes shares repurchased by ATI from employees to satisfy employee-owed taxes on share-based compensation.

(b) Share repurchases are inclusive of amounts for any relevant commissions.

(c) Excludes excise taxes incurred on share repurchases.

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Cumulative Total Stockholder Return

The graph set forth below shows the cumulative total stockholder return (i.e., price change plus reinvestment of dividends) on our common stock from January 3, 2021 through December 28, 2025, as compared to the S&P 500 Index, the S&P MidCap 400 Industrials Index and the Russell 2000 Index. The graph assumes that $100 was invested on January 3, 2021. The stock performance information included in this graph is based on historical results and is not necessarily indicative of future stock price performance.

Source: Standard & Poor’s

Item 6. [Reserved]

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following Management's Discussion and Analysis of Financial Condition and Results of Operations (MD&A) is intended to help the reader understand our results of operations and financial condition or the year ended December 28, 2025 (fiscal year 2025) as compared to the year ended December 29, 2024 (fiscal year 2024). The MD&A includes certain statements that are forward-looking statements. Actual results or performance could differ materially from those encompassed within such forward-looking statements as a result of various factors, including those described below. The MD&A should be read in conjunction with our consolidated financial statements and notes thereto included in Part II, Item 8 (Financial statements and Supplementary Data) of this Form 10-K. Information on the Company’s results of operations, financial condition and liquidity for fiscal year 2024 as compared to the year ended December 31, 2023 (fiscal year 2023) is included in our Annual Report on Form 10-K in Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations” filed on February 21, 2025 and is incorporated herein by reference.

ATI Overview

ATI is a global manufacturer of technically advanced specialty materials and complex components. We are a market leader in manufacturing differentiated products that require our materials science capabilities and unique process technologies, including our new product development competence. Our largest markets are aerospace & defense, representing approximately 68% of total sales, led by products for jet engines and airframes. Additionally, we have a strong presence in the specialty energy end market, which includes products for nuclear and renewable energy applications. In aggregate, these markets represent over 73% of our total revenue. We also sell to several other end markets, including industrial, electronics and medical.

We operate in two business segments: HPMC and AA&S. The HPMC segment produces a wide range of high performance materials, components, and advanced metallic powder alloys. These products are made from nickel-based alloys and superalloys, titanium and titanium-based alloys, and a variety of other specialty materials. HPMC’s capabilities range from cast/wrought and powder alloy development to production of highly engineered components, and 3D-printed aerospace products. The HPMC segment’s primary focus is on maximizing jet engine materials and components growth, with

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approximately 92% of its revenue derived from the aerospace & defense markets, including nearly 68% from products for commercial jet engines. Commercial aerospace products have been the main source of sales and EBITDA growth for HPMC over the last several years and are expected to continue to drive HPMC and overall ATI results in the future. HPMC has also experienced strong growth in defense products, with fiscal year 2025 sales growth of 24%. Sales of defense products comprise almost 11% of HPMC's total sales.

The AA&S segment produces nickel-based alloys, titanium and titanium-based alloys, and specialty alloys in a variety of forms including plate, sheet, and strip products. AA&S focuses on high-value materials that are utilized in technically challenging and extreme environments, which require materials that can withstand extreme heat, radiation and corrosion. AA&S continued its focus of growing sales to the aerospace & defense end markets, with fiscal year 2025 sales to those markets increasing 15%. Aerospace & defense now comprises approximately 41% of AA&S total revenue. AA&S also serves customers across several other markets, notably specialty energy and conventional energy, as well as electronics and certain industrial markets.

Overview of Fiscal Year 2025 Financial Performance

Sales in fiscal year 2025 increased 5%, to $4.6 billion, and gross profit increased 12%, to $1.0 billion, compared to fiscal year 2024, reflecting increased demand for products within our aerospace & defense end markets, partially offset by softness in the medical, other industrial, and specialty energy end markets. International sales, including both U.S. exports and foreign sales from our foreign operations, were $1.9 billion in fiscal year 2025 and represented 43% of total sales, compared to $1.8 billion or 42% of total sales in fiscal year 2024.

Results for fiscal year 2025 included $70 million of net pre-tax charges and fiscal year 2024 included $17 million of net pre-tax gains as further described in the Results of Operations section below. The Company’s net income for fiscal year 2025 was $404.3 million, or $2.85 per share. ATI Adjusted EBITDA for fiscal year 2025 was $859.3 million, or 18.7% of sales, compared to $729.1 million, or 16.7% of sales, for fiscal year 2024. See further explanation below for non-GAAP definitions and calculations.

A summary of our results is as follows:

Fiscal Year

(Dollars in millions, except per share amounts) 2025 2024

Gross profit % of sales 22.0 % 20.6 %

Income before income taxes $ 522.3 $ 486.1

Net income attributable to ATI $ 404.3 $ 367.8

Diluted net income attributable to ATI per common share $ 2.85 $ 2.55

Key financial highlights of fiscal year 2025 include the following:

•Year-over-year sales growth of approximately 5%, with ATI’s 2025 sales representing our highest total since 2012. Fiscal year 2025 sales to the aerospace & defense markets increased 14% and represented 68% of our total sales, compared to 62% of total sales in fiscal year 2024.

•Growth in aerospace & defense drove year-over-year increases in operating income of 5% and net income attributable to ATI of 10%. Adjusted EBITDA improved to $859.3 million compared to $729.1 million in 2024, an increase of 18%. Adjusted EBITDA as a percentage of sales was 18.7% for fiscal year 2025, an improvement of 200 basis points compared to fiscal year 2024.

•We generated cash flow of $614.3 million from operating activities in fiscal year 2025, an increase of almost 51% compared to fiscal year 2024, as we continued efforts to focus on operational improvements to positively impact the inventory intensity of our business and reduce the required investment of managed working capital in relation to our growth in sales. Managed working capital as a percent of sales was 32.5% as of December 28, 2025, compared to 30.9% as of December 29, 2024, primarily due to the timing of payments to vendors and the 5% increase in 2025 sales.

•We continued our disciplined approach to capital allocation, funding growth while returning cash to our shareholders through the repurchase of our stock. We repurchased approximately 6.4 million shares of ATI stock for $470 million in fiscal year 2025. We have approximately $120 million of share repurchase authorization remaining under the plan approved by our Board of Directors.

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•We continued to deleverage our balance sheet, repaying $150 million of debentures in the fourth quarter of 2025. Further, we reduced our interest expense in fiscal year 2025 by approximately $9.0 million compared to fiscal year 2024, which was due to the redemption of the $291.4 million outstanding principal amount of 3.5% Convertible Senior Notes due 2025 (2025 Convertible Notes) during the third quarter of 2024.

Results of Operations

Fiscal Year 2025 Compared to Fiscal Year 2024

Sales

Fiscal year 2025 sales increased $225.3 million to $4.6 billion compared to fiscal year 2024, primarily due to increased demand for commercial jet engine products and defense applications. Total sales to the aerospace & defense markets increased by 14% compared to fiscal year 2024. This increase was partially offset by lower sales to the medical, specialty energy, and certain industrial end markets.

Comparative information for our overall revenues by end market, and their respective percentages of total revenues, is as follows:

(In millions) Fiscal Year

Aerospace & Defense:

Other Markets:

Comparative information for our major products, based on their percentages of revenues, is as follows. Hot-Rolling and Processing Facility (HRPF) conversion service sales in the AA&S segment are excluded from this presentation.

Fiscal Year

Nickel-based alloys and specialty alloys 46 % 45 %

Precision forgings, castings and components 22 % 19 %

Titanium and titanium-based alloys 18 % 18 %

Zirconium and related alloys 9 % 9 %

PRS products 5 % 9 %

Sales by geographic area and as a percentage of total sales, were as follows:

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(In millions) Fiscal Year

Gross Profit

Fiscal year 2025 gross profit was $1,007.0 million, or 22.0% of sales, a $108.8 million increase compared to fiscal year 2024. Gross profit in fiscal year 2025 includes $23.6 million of start-up and transaction-related costs, which are excluded from Adjusted EBITDA. Fiscal year 2025 gross profit also includes a benefit of $7.2 million related to the recognition of previously deferred employee retention tax credits, of which $4.4 million related to the HPMC segment and $2.8 million related to the AA&S segment.

Fiscal year 2024 gross profit was $898.2 million, or 20.6% of sales, and included $15.3 million primarily for start-up and transaction-related costs, which are excluded from Adjusted EBITDA. Fiscal year 2024 gross profit also included a benefit of $16.7 million related to the recognition of previously deferred employee retention tax credits, of which $9.0 million of the benefit was recognized in the HPMC segment and $7.7 million in the AA&S segment.

The overall 140 basis points improvement in fiscal year 2025 gross profit margin as compared to fiscal year 2024 gross profit was primarily due to favorable sales mix and pricing as well as higher volumes.

Selling and Administrative Expenses

Selling and administrative expenses for fiscal year 2025 were $365.1 million, an increase of $22.8 million from 2024. The increase was primarily due to professional fees associated with transformation activities, losses on the sale of customer accounts receivable, and higher incentive compensation costs. Transformation-related costs were $17.1 million and losses on the sale of customer accounts receivable were $7.8 million. In addition, fiscal year 2025 selling and administrative expenses included $2.2 million of transaction-related costs. The charges for transformation-related costs, losses on the sale of customer accounts receivable, and transaction-related costs are excluded from Adjusted EBITDA.

Fiscal year 2024 included $2.7 million of transaction-related costs and costs associated with our European restructuring, which are excluded from Adjusted EBITDA. Fiscal year 2024 also included charges of $11.8 million primarily related to a commercial negotiation with a customer. HPMC segment results reflect $6.3 million of this charge, while the remaining $5.5 million is reflected in the AA&S segment results.

Restructuring (Credits) Charges

For the fiscal year ended December 28, 2025, restructuring credits were $1.9 million due to a reduction in severance-related reserves for a previous restructuring, primarily in the AA&S segment. These credits are excluded from Adjusted EBITDA.

For the fiscal year ended December 29, 2024, restructuring charges were $4.1 million for severance-related reserves primarily related to cost reduction actions in our domestic operations. These charges are excluded from Adjusted EBITDA.

Loss (Gain) on Asset Sales and Sales of Businesses, net

The fiscal year 2025 loss on assets sales and sales of businesses, net is comprised of an $0.8 million gain for the sale of a non-core business previously reported in the HPMC segment, for which ATI received $19.3 million of proceeds, net of transaction costs and a working capital adjustment. This gain is offset by a $3.7 million loss of the sale of certain non-core European operations from the HPMC segment for which ATI received $5.0 million of proceeds, net of transaction costs. The proceeds from both transactions were reported as an investing activity on the consolidated statement of cash flow.

The fiscal year 2024 gain on asset sales and sales of businesses, net was primarily due to a $52.9 million gain on the sale of our precision rolled strip operations, for which ATI received $48.0 million of proceeds, net of transaction costs, that were reported as an investing activity on the consolidated statement of cash flows.

Pension Remeasurement Gains and Losses

The Company recognizes gains and losses from the remeasurement of the projected benefit obligation and plan assets for defined benefit pension plans immediately in earnings through net periodic pension benefit cost. The Company completes the remeasurements of these plans in the fourth quarter of each fiscal year and, as a result, we recognized pension remeasurement losses of $18.6 million and $14.1 million in fiscal years 2025 and 2024, respectively. These losses are excluded from Adjusted EBITDA and recorded in nonoperating retirement benefit income/expense on the consolidated statements of operations.

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Interest Expense, Net

Interest expense, net of interest income and interest capitalization, was $98.6 million in fiscal year 2025, compared to $108.2 million in fiscal year 2024. The decrease in fiscal year 2025 compared to fiscal year 2024 is due to the redemption of the 2025 Convertible Notes during the third quarter of 2024. Further, interest expense is presented net of interest income of $12.1 million in fiscal year 2025 and $16.0 million in fiscal year 2024. Interest expense in fiscal years 2025 and 2024 was reduced by $10.6 million and $11.8 million, respectively, related to interest capitalization on large, strategic capital projects.

Other Income, Net

Other income, net for fiscal year 2025 of $14.6 million included a gain of $10.5 million from the sale of certain oil and gas rights. Other income, net for fiscal year 2024 of $14.4 million included a gain of $11.6 million from the sale of certain oil and gas rights.

Income Taxes

The fiscal year 2025 effective tax rate was 19.9%, resulting in an income tax provision of $103.7 million, compared to an effective tax rate of 21.3%, resulting in an income tax provision of $103.4 million in fiscal year 2024. The effective tax rates for fiscal years 2025 and 2024 included discrete tax benefits of $6.0 million and $6.2 million, respectively. The discrete tax benefits in fiscal years 2025 and 2024 included $4.3 million and $3.3 million, respectively, for share-based compensation.

The 140 basis point decrease in the effective tax rate in fiscal year 2025 as compared to fiscal year 2024 was primarily due to higher deductions for benefits that were previously limited due to our net operating losses, such as foreign derived intangible income.

Net Income

Net income attributable to ATI was $404.3 million, or $2.85 per share, in fiscal year 2025, compared to $367.8 million, or $2.55 per share, for fiscal year 2024.

Results by Business Segment

As discussed above, we operate in two business segments: HPMC and AA&S. HPMC sales increased 7% in fiscal year 2025 compared to fiscal year 2024, primarily due to higher aerospace & defense market sales. Increased demand for commercial jet engines and defense applications resulted in a 14% increase in sales to the aerospace & defense markets. Full fiscal year 2025 AA&S sales increased 3% due to a 15% increase in aerospace & defense sales and a 10% increase in conventional energy market sales partially offset by softness in other certain other markets, including specialty energy, medical and electronics.

Comparative financial information (in millions) for our segments and corporate operations for the year-to-date periods ended December 28, 2025 and December 29, 2024 is shown below.

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(In millions) Fiscal Year Ended

December 28, December 29, December 31,

Sales:

Segment EBITDA(a):

High Performance Materials & Components $ 575.8 $ 461.4 $ 433.6

Corporate, Closed Operations and Other (income) expense(b):

Closed operations and other (income) expense (2.3) (10.8) 13.3

Total Corporate, Closed Operations and Other expense $ 65.5 $ 53.2 $ 75.6

Depreciation & amortization

High Performance Materials & Components 84.2 71.6 71.1

(a)The Company’s Chief Operating Decision Maker (“CODM”) utilizes the Segment EBITDA as a key metric to evaluate segment performance. Our measure of Segment EBITDA, which we use to analyze the performance and results of our business segments, excludes net interest expense, income taxes, depreciation and amortization, special charges, unallocated corporate expenses, closed operations and other (income) expense. See Note 18 for the reconciliation of Segment EBITDA to Income before taxes.

(b)Amounts exclude depreciation and amortization.

High Performance Materials & Components

Fiscal Year Fiscal Year

Segment EBITDA as a percentage of sales 23.6 % 20.3 %

International sales as a percentage of sales 45.3 % 50.2 %

Our HPMC segment produces a wide range of high performance materials, including titanium and titanium-based alloys, nickel- and cobalt-based alloys and superalloys, advanced powder alloys and other specialty materials, in long product forms such as ingot, billet, bar, rod, wire, shapes and rectangles, and seamless tubes, plus precision forgings, components, and machined parts.

Fiscal Year 2025 Compared to Fiscal Year 2024

Sales of $2.4 billion for the HPMC segment in fiscal year 2025 increased 7% compared to fiscal year 2024, primarily due to strong demand in aerospace & defense markets, which were up 14% compared to fiscal year 2024. Sales to the commercial aerospace market increased 13% due to an increase in commercial jet engine sales of 21%, which was partially offset by a decrease in commercial air frame sales of 16%. In addition, sales of defense products increased 24% compared to fiscal year 2024. These increases were partially offset by lower sales to the medical, specialty energy, and other industrial end markets.

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Comparative information for our HPMC segment revenues by market, the respective percentages of overall segment revenues for the fiscal years 2025 and 2024, and the percentage change in revenues by market for fiscal year 2025 is as follows:

(In millions) Fiscal Year

Aerospace & Defense:

Other Markets:

Electronics — — % 3.0 — % (3.0) (100) %

Conventional Energy 6.1 — % 9.8 1 % (3.7) (38) %

We utilize LTAs for our specialty materials, including powders, parts and components, with certain of our customers, including several aerospace market OEMs, to reduce their supply uncertainty. These LTAs cover sales of ATI’s specialty materials, precision forgings, components, and machined parts that are used in both next-generation and legacy aircraft platforms, including jet engines. Our LTAs include a titanium products supply agreement for aircraft airframes and structural components with Boeing. This LTA covers value-added titanium products and provides opportunities for greater use of ATI’s next generation and advanced titanium alloys in both long product and flat-rolled product forms. The agreement includes both long-product forms that are manufactured within the HPMC segment, and a significant amount of plate products that are manufactured utilizing assets of both the HPMC and AA&S segments. Revenues and profits associated with these titanium products covered by the Boeing LTA are included primarily in the results for the HPMC segment. The HPMC segment also includes revenues and profits under our LTA with Airbus for titanium airframe products.

We have LTAs with several aircraft engine manufacturers, including GE Aviation and Safran, to supply premium titanium alloys, nickel-based alloys, and vacuum-melted specialty alloys products for commercial and military jet engine applications. In addition, we have LTAs with Rolls-Royce plc for the supply of disc-quality mill products and precision forgings for commercial jet engine applications and with Pratt & Whitney to provide isothermal and conventional forgings for use in jet engines. We also supply products to other important parts of the aircraft market such as helicopters and rotary engine fixed wing aircraft.

New airframe designs contain a larger percentage of titanium alloys, and the jet engines that power them use newer nickel and titanium-based alloys for improved performance and more economical operating costs. Boeing and Airbus continue to have multi-year backlogs of orders for both legacy models and next-generation aircraft, and there are over 30,000 jet engines with firm orders (Aero Engine News, Fourth Quarter 2025). Due to manufacturing cycle times, demand for our specialty materials leads the deliveries of new aircrafts by approximately 6 to 12 months.

Use of these newer materials, particularly for jet engine applications, is expected to continue to increase for several years, with strong growth expected in powder metal alloys, including increased usage of iso-thermal forging and additive manufacturing production processes.

In addition, as our specialty materials are used in rotating components of jet engines, demand for our products for spare parts is impacted by aircraft flight activity and engine refurbishment requirements of U.S. and foreign aviation regulatory authorities. As the number of aircraft in service and flight activity increases, the need for our materials associated with engine refurbishment is expected to increase.

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Comparative information for HPMC’s major product categories based on their percentages of the segment’s overall revenue is as follows:

Fiscal Year

Nickel-based alloys and specialty alloys 43 % 41 %

Precision forgings, castings and components 40 % 36 %

Titanium and titanium-based alloys 17 % 23 %

HPMC Segment EBITDA for fiscal year 2025 increased 25% to $575.8 million, or 23.6% of sales, compared to $461.4 million, or 20.3% of sales, in fiscal year 2024. The fiscal year 2025 increase in Segment EBITDA as a percentage of sales was primarily due to favorable sales mix and pricing as well as higher volumes. Results in fiscal year 2025 included $4.4 million of benefits related to the recognition of previously deferred employee retention tax credits. Results in fiscal year 2024 included $9.0 million of benefits related to the recognition of previously deferred employee retention tax credits, which were partially offset by a charge of approximately $6.3 million due to a commercial negotiation with a customer and higher incentive compensation, maintenance and outsourcing costs.

Advanced Alloys & Solutions

Fiscal Year Fiscal Year

Segment EBITDA as a percentage of sales 16.3 % 15.4 %

International sales as a percentage of sales 39.2 % 33.2 %

Fiscal Year 2025 Compared to Fiscal Year 2024

Sales of $2.1 billion for the AA&S segment in fiscal year 2025 increased 3% compared to fiscal year 2024, primarily due to an increase in aerospace & defense sales of 15%, driven by growth for commercial airframe products and jet engine products, as well as a 10% increase in sales to the conventional energy market. These increases were partially offset by lower sales to medical, construction and mining and other industrial markets.

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Comparative information for our AA&S segment revenues by market, the respective percentages of overall segment revenues, for the fiscal years 2025 and 2024, and the percentage change in revenues by market for fiscal year 2024 is as follows:

(In millions) Fiscal Year

Aerospace & Defense:

Other Markets:

Our AA&S segment produces zirconium and related alloys including hafnium and niobium, nickel-based alloys, titanium and titanium-based alloys, and specialty alloys in a variety of forms including plate, sheet, and PRS products. AA&S also provides hot-rolling conversion services at its HRPF, including carbon steel products under several LTAs.

Comparative information for the AA&S segment’s major product categories, based on their percentages of revenue are presented in the following table. HRPF conversion service sales are excluded from this presentation.

Fiscal Year

Nickel-based alloys and specialty alloys 50 % 49 %

Zirconium and related alloys 19 % 19 %

Titanium and titanium-based alloys 19 % 13 %

PRS products 12 % 19 %

Segment EBITDA was $349.0 million, or 16.3% of sales, an 9% increase from Segment EBITDA of $320.9 million, or 15.4% of sales, in fiscal year 2024. The margin increase compared to the prior year was primarily due to favorable pricing for exotic alloys and improved sales mix on higher demand for nickel-based alloys and titanium mill products. Results in fiscal year 2025 included $2.8 million of benefits related to the recognition of previously deferred employee retention tax credits. Fiscal year 2024 also included $7.7 million of benefits related to the recognition of previously deferred employee retention tax credits, which were partially offset by a charge of approximately $5.5 million due to a commercial negotiation with a customer and higher incentive compensation and maintenance costs.

Corporate Items

Corporate expenses, which are primarily included in selling and administrative expenses in the statement of operations, were $67.8 million in fiscal year 2025 compared to $64.0 million in fiscal year 2024. The increase in expenses in fiscal year 2025 as compared to fiscal year 2024 was primarily due to higher incentive compensation costs and prior year benefits due to insurance settlements.

Closed operations and other income/expenses are presented primarily in selling and administrative expenses in the consolidated statements of operations and include legal, environmental, retirement benefits and insurance obligations associated with closed operations as well as gains from the sale of non-core assets. Closed operations and other expenses provided income of $2.3

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million in fiscal year 2025 and $10.8 million in fiscal year 2024. Fiscal year 2025 includes a $10.5 million gain on the sale of certain oil and gas rights, included within other income, net, on the consolidated statement of operations. This gain was offset by unfavorable foreign currency transaction impacts compared to the prior year period. Fiscal year 2024 includes an $11.6 million gain on the sale of certain oil and gas rights, included within other income, net, on the consolidated statement of operations. Fiscal year 2024 also includes a $2.3 million gain on the sale of assets for our idled Houston, PA facility included within gain on asset sales and sales of businesses, net, on the consolidated statement of operations.

Managed Working Capital

As part of managing the performance of our business, we focus on controlling Managed Working Capital, which we define as gross accounts receivable, short-term contract assets and gross inventories, less accounts payable and short-term contract liabilities. We exclude the effects of inventory valuation reserves and reserves for uncollectible accounts receivable when computing this non-GAAP performance measure, which is not intended to replace Working Capital or to be used as a measure of liquidity. We employ several strategies to actively manage our Managed Working Capital, seeking to effectively balance the need to maintain appropriate levels of Managed Working Capital to support our growth and operations, while deploying our cash efficiently. Our strategies to actively manage our Managed Working Capital include, but are not limited to, taking advantage of favorable customer and supplier payment terms, participating in supplier financing programs, accounts receivable factoring arrangements and other customer financing programs, managing the timing of purchases of raw materials, and leveling manufacturing process throughput and shipping to limit periodic increases in Managed Working Capital. We assess Managed Working Capital performance as a percentage of the prior three months’ annualized sales to evaluate the asset intensity of our business.

At December 28, 2025, Managed Working Capital was 32.5% of annualized total ATI sales compared to 30.9% of annualized sales at December 29, 2024. The increase in Managed Working Capital as a percentage of annualized sales year over year was primarily due to inventory builds to support increased operating levels and the timing of shipments and vendor payments. The $80.8 million increase in overall Managed Working Capital in fiscal year 2025 is detailed in the table below. Days sales outstanding, which measures actual collection timing for accounts receivable, improved slightly by 3% as of December 28, 2025 compared to fiscal year 2024. Gross inventory turns, which measures how many times we turn over our inventory relative to cost of sales in a year, worsened by 8% in fiscal year 2025 compared to fiscal year 2024. We continue our focus on operational improvements to positively impact the inventory intensity of our business and reduce the required investment of Managed Working Capital in our growing business.

The computations of Managed Working Capital at December 28, 2025 and December 29, 2024 reconciled to the financial statement line items as computed under U.S. GAAP, were as follows.

Short-term contract assets 72.8 75.6

Short-term contract liabilities (146.4) (169.4)

Allowance for doubtful accounts 4.2 15.0

Net managed working capital held for sale — 8.5

Managed working capital as a % of annualized sales 32.5 % 30.9 %

December 29, 2025 change in managed working capital $ 80.8

Financial Condition and Liquidity

On June 13, 2025, we amended our Asset Based Lending (ABL) Credit Facility, which is collateralized by the accounts receivable and inventory of our operations and also provides us with the option of including certain machinery and equipment as additional collateral for purposes of determining availability under the facility. This amendment extended the facility through June 2030. The amended ABL includes a $600 million revolving credit facility, a letter of credit sub-facility of up to $200 million, a $200 million term loan (Term Loan), and a swing loan facility of up to $60 million. Additionally, the amendment gives the Company the ability, through June 13, 2026, and as long as no default or event of default has occurred and is continuing, to borrow an additional term loan of up to $100 million in total, using one or two draws (the Delayed-Draw

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Term Loan). The ABL Term Loan and any Delayed-Draw Term Loan can be prepaid in increments of $25 million if certain minimum liquidity conditions are satisfied. In addition, we have the right to request an increase of up to $300 million under the revolving credit facility for the duration of the ABL.

As of December 28, 2025, there were no outstanding borrowings under the revolving credit portion of the ABL, and $29.3 million was utilized to support the issuance of letters of credit. There were average revolving credit borrowings of $2.6 million bearing an average annual interest rate of 6.5% under the ABL during fiscal year 2025. There were no revolving credit borrowings under the ABL during fiscal year 2024.

The ABL Term Loan and Delayed-Draw Term Loan have an interest rate of 2.0% above the adjusted Secured Overnight Financing Rate (SOFR). The applicable interest rate for revolving credit borrowings under the ABL credit facility includes interest rate spreads based on available borrowing capacity that range between 1.25% and 1.75% for SOFR-based borrowings and between 0.25% and 0.75% for base rate borrowings.

The ABL credit facility contains a financial covenant whereby we must maintain a fixed charge coverage ratio of not less than 1.00:1.00 after an event of default has occurred and is continuing or if the undrawn availability under the ABL revolving credit portion of the facility is less than the greater of (i) 10% of the then applicable maximum loan amount under the revolving credit portion of the ABL and the outstanding ABL Term Loan balance, or (ii) $60.0 million. We were in compliance with the fixed charge coverage ratio as of December 28, 2025.

During 2025, we received $26.8 million of proceeds from the sale of non-core businesses previously reported in the HPMC segment and proceeds of $11.1 million from property, plant and equipment sales, primarily for oil and gas rights.

At December 28, 2025, we had total liquidity of $1.1 billion, comprised of $417 million of cash and cash equivalents, $569 million of undrawn capacity under the ABL credit facility, and up to $100 million of availability under the Delayed-Draw Term Loan. Our next meaningful debt maturity is $350 million of Senior Notes in the fourth quarter of fiscal year 2027.

Our U.S. qualified defined benefit plan has approximately 2,000 participants. Based on current actuarial assumptions, we are required to make a $4 million contribution to the plan during fiscal year 2026. Using our long-term weighted average expected rate of return on pension plan assets and other actuarial assumptions, we expect to have approximately $40 million of minimum cash funding requirements to the defined benefit pension plan over the next ten years. Minimum cash funding requirements are not expected to be significant in any individual year. However, these funding estimates are subject to significant uncertainty including the actual pension trust assets and the discount rates used to measure pension liabilities.

Periodically, our Board of Directors authorizes the repurchase of ATI Common stock (the “Share Repurchase Program”), the most recent of which was $700 million that was announced in September 2024. In fiscal year 2025, ATI used $470 million to repurchase 6.4 million shares of its common stock under the Share Repurchase Program. As of December 28, 2025, there is $120 million of authorization remaining under the Share Repurchase Program. Repurchases under these programs can be made in the open market or in privately negotiated transactions, with the amount and timing of repurchases depending on market conditions and corporate needs. Open market repurchases are structured to occur within the pricing and volume requirements of SEC Rule 10b-18. The current Share Repurchase Program has no time limit, does not obligate the Company to repurchase any specific number of shares, and may be modified, suspended, or terminated at any time by the Board of Directors without prior notice.

In managing our overall capital structure, we focus on the ratio of net debt to Adjusted EBITDA, which we use as a measure of our ability to repay our incurred debt. We define net debt as the total principal balance of our outstanding indebtedness excluding deferred financing costs, net of cash, at the balance sheet date. See the explanations above for our definitions of Adjusted EBITDA and EBITDA, which are non-GAAP measures and are not intended to represent, and should not be considered more meaningful than, or as alternatives to, a measure of operating performance as determined in accordance with U.S. GAAP. Our ratio of net debt to Adjusted EBITDA (Adjusted EBITDA Leverage Ratio) measures net debt at the balance sheet date to Adjusted EBITDA as calculated on the trailing twelve-month period from this balance sheet date.

Our Debt to Adjusted EBITDA Leverage Ratio and Net Debt to Adjusted EBITDA Leverage ratio improved in fiscal year 2025 compared to fiscal year 2024, resulting from higher earnings and lower debt as a result of the redemption of the 2025 debentures. The reconciliations of our Adjusted EBITDA Leverage Ratios to the balance sheet and income statement amounts as reported under U.S. GAAP are as follows:

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Net income attributable to ATI $ 404.3 $ 367.8

Net income attributable to noncontrolling interests 14.3 14.9

Depreciation and amortization 168.1 151.5

Income tax provision (benefit) 103.7 103.4

Pension remeasurement loss 18.6 14.1

Restructuring and other charges 48.8 22.1

Loss (gain) on asset sales and sale of business 2.9 (52.9)

Add: Debt issuance costs 11.6 14.2

Debt to Adjusted EBITDA 2.05 2.62

Net Debt to Adjusted EBITDA 1.56 1.63

We believe that internally generated funds, current cash on hand and available borrowings under the ABL credit facility will be adequate to meet our liquidity needs, including the scheduled debt maturity in the fourth quarter of fiscal year 2027. We regularly review our capital structure, various financing alternatives and conditions in the debt and equity markets in order to opportunistically enhance our capital structure and reduce financing costs. As a result, we may seek to refinance or retire existing indebtedness, incur new or additional indebtedness or issue equity or equity-linked securities, in each case, depending on market and other conditions. Further, in the event we seek additional or new financing, the cost, terms and conditions of such borrowings would be impacted by our credit rating. As of December 28, 2025, we have no off-balance sheet arrangements as defined in Item 303(a)(4) of SEC Regulation S-K.

Cash Flow

Cash provided by operations was $614.3 million for fiscal year 2025 and $407.2 million fiscal year 2024. The 2025 period improvement was due to higher net income and improved working capital changes compared to the 2024 period, including cash flows from accounts receivable. Accounts receivable were positively impacted by the sale of $80 million of accounts receivable in exchange for cash under the new Receivables Facility. Working capital balances, and consequently cash from operations, can fluctuate throughout any operating period based upon the timing of receipts from customers and payments to vendors. However, we actively manage our working capital to allow for the required flexibility to meet our strategic objectives. Other significant fiscal year 2025 operating cash flow items included payment of 2024 annual incentive compensation. Other significant fiscal year 2024 operating cash flow items included payment of 2023 annual incentive compensation.

Cash used in investing activities was $234.5 million in fiscal year 2025, reflecting $280.6 million in capital expenditures to grow our capacity and capabilities with a focus on our aerospace & defense market. These investing activity outflows were partially offset by $26.8 million of proceeds from the sale of non-core businesses previously reported in the HPMC segment and proceeds of $11.1 million from property, plant and equipment sales, primarily for oil and gas rights. We expect to fund our capital expenditures with cash on hand, cash flow generated from our operations and, if needed, by using a portion of the ABL credit facility. Cash used in investing activities was $159.6 million in fiscal year 2024, reflecting $239.1 million in capital expenditures to grow our capacity and capabilities with a focus on aerospace & defense. These investing activity outflows were partially offset by $48.0 million of proceeds from the sale of our New Bedford, MA operations and Remscheid, Germany operations and $27.6 million of proceeds from property, plant and equipment sales, which included $11.6 million of proceeds on the sale of certain oil and gas rights and $3.5 million of proceeds received for the sale of assets for our idled Houston, PA facility.

Cash used by financing activities in fiscal year 2025 was $699.9 million, which included $470.0 million to repurchase 6.4 million shares of ATI stock under our Share Repurchase Program, $150.0 million for the repayment of our 2025 debentures and $13.2 million in dividend payments to the 40% noncontrolling interest in our PRS joint venture in China. Cash provided by financing activities in fiscal year 2024 was $260.4 million, which included $260.0 million to repurchase 5.3 million shares of

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ATI stock under our Share Repurchase Program and $16.0 million in dividend payments to the 40% noncontrolling interest in our PRS joint venture in China, partially offset by $76.1 million in cash received from the settlement of the capped call as a result of the redemption of the 2025 Convertible Notes.

At December 28, 2025, cash and cash equivalents on hand totaled $416.7 million, a $304.5 million decrease from fiscal year-end 2024. Cash and cash equivalents held by our foreign subsidiaries was $183.7 million at December 28, 2025, of which $97.6 million was held by our PRS joint venture in China.

Contractual Obligations

A summary of required payments under financial instruments (excluding accrued interest) and other commitments are presented below.

(In millions) Total Less than 1year 1-3years 4-5years After 5years

Contractual Cash Obligations

Unconditional Purchase Obligations

Other Financial Commitments

Guarantees $ 17.8

(A)Amounts exclude $72 million for certain finance lease contracts the Company has agreed to enter into. See Note 11, Leases for further information.

(B)Amounts include contractual interest payments using the interest rates in effect as of December 28, 2025 applicable to the Company’s ABL Term Loan due 2030, the 5.875% Senior Notes due 2027, the 4.875% Senior Notes due 2029, the 7.25% Senior Notes due 2030, and the 5.125% Senior Notes due 2031.

(C)Amounts include operating lease obligations at their undiscounted value. These obligations are presented in other current liabilities and other long-term liabilities on the consolidated balance sheets at their discounted value, using applicable interest rates. See Note 11, Leases for further information.

(D)Based on current actuarial studies, amounts include payments for the next 10 years, which are not significant, to defined benefit pension plans, assuming the expected long-term returns on pension assets are achieved. Projections of minimum required payments to the U.S. qualified defined benefit pension plan are subject to significant uncertainty based on a number of factors including actual pension plan asset returns, changes in estimates of participant longevity, and changes in interest rates. Amounts also include actuarial projections of payments under other post-employment benefit plans for the next 10 years. In most retiree healthcare plans, our contributions are capped based on the cost as of a certain date. See Note 14, Retirement Benefits for further information.

(E)We have contracted for physical delivery for certain of our raw materials to meet a portion of our needs. These contracts are based upon fixed or variable price provisions. We used current market prices as of December 28, 2025, for raw material obligations with variable pricing.

(F)We have various contractual obligations that extend through fiscal year 2031 for services involving production facilities, information technology services and administrative operations. Our purchase obligation as disclosed represents the estimated termination fees payable if we were to exit these contracts.

(G)At December 28, 2025, drawn amounts on the U.S. facility were $29.3 million utilized for standby letters of credit under the $600 million ABL credit facility, which renew annually. These standby letters of credit are used to support: $19.6 million in workers’ compensation and general insurance arrangements, $5.4 million related to environmental matters and $4.3 million for performance assurances.

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Commitments and Contingencies

At December 28, 2025, our reserves for environmental remediation obligations totaled approximately $15 million, of which $7 million was included in other current liabilities. These reserves included estimated probable future costs of: $2 million for federal Superfund and comparable state-managed sites; $7 million for formerly owned or operated sites for remediation or indemnification obligations; and $6 million for owned or controlled sites at which our operations have been or plan to be discontinued. We continue to evaluate whether we may be able to recover a portion of future costs for environmental liabilities from third parties and to pursue such recoveries where appropriate. The timing of expenditures depends on a number of factors that vary by site. ATI expects that it will expend present accruals over many years and that remediation of all sites with which it has been identified will be completed within thirty years.

Asset retirement obligations (AROs) recorded by the Company were $8 million at December 28, 2025. These AROs related to landfill closures, decommissioning costs, facility leases and conditional AROs associated with manufacturing activities using what may be characterized as potentially hazardous materials. During fiscal year 2024, we derecognized $10 million of AROs in connection with the sale of our precision rolled strip operations.

Based on currently available information, it is reasonably possible that the costs for active matters may exceed our recorded reserves by as much as $16 million. However, future investigation or remediation activities may result in the discovery of additional hazardous materials, potentially higher levels of contamination than discovered during prior investigation, and may impact costs of the success or lack thereof in remedial solutions. Therefore, future developments, administrative actions or liabilities relating to environmental matters could have a material adverse effect on the ATI’s consolidated financial condition or results of operations.

Retirement Benefits

ATI’s defined benefit pension plans are closed to new entrants, and at most ATI operations with pension participants, the plans are frozen for all future benefit accruals, with less than 700 participants still accruing benefit service. Additionally, all of the remaining collectively-bargained defined benefit retiree health care plans at ATI’s operations are now closed to new entrants, with cost caps in place for these obligations. As a result of these actions, ATI’s retirement savings and other postretirement benefit programs have largely transitioned to a defined contribution structure. From fiscal years 2013 to 2022, five annuity buyouts of retired participants and two voluntary cash out programs of deferred participants helped to reduce the total participants in ATI’s U.S. qualified defined benefit pension plans by more than 60%. During the fourth quarter of fiscal year 2023, we purchased group annuity contracts from an insurer covering approximately 85% of our U.S. qualified defined benefit pension plan obligations. Under these contracts, we transferred the pension obligations and associated assets for approximately 8,200 plan participants to the selected insurance company. To facilitate this pension derisking strategy, we completed a voluntary cash out for term vested employees and contributed $222 million to our pension plan in the third quarter of fiscal year 2023, to fully fund remaining pension liabilities ahead of this annuity transaction. After these actions, our U.S. qualified defined benefit pension plan includes approximately 2,000 participants.

At December 28, 2025, our defined benefit pension plans were approximately 86% funded in accordance with U.S. GAAP, and were remeasured at that date using a 5.90% discount rate to measure the projected benefit obligation. Discount rates used to measure pension liabilities for U.S. qualified defined benefit plans for ERISA funding purposes are calculated on a different basis using an IRS-determined segmented yield curve. Funding requirements are also affected by IRS-determined mortality assumptions, which may differ from those used under accounting standards. Based on current actuarial assumptions, we are required to make a $4 million contribution to our qualified defined benefit pension plan during fiscal year 2026. Using our long-term weighted average expected return on pension plan assets and other actuarial assumptions, we expect to have approximately $40 million of minimum cash funding requirements to the qualified defined benefit pension plan over the next ten years. Minimum cash funding requirements are not expected to be significant in any individual year. However, these estimates are subject to significant uncertainty, including the performance of our pension trust assets and the discount rates used to measure pension liabilities. Pension trust asset performance for both our accounting and ERISA funding calculations is determined using the market value of plan assets at the end of each year.

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Reconciliation of Adjusted EBITDA to Net Income

ATI utilizes Adjusted EBITDA, which is a non-GAAP financial measure, to assist in assessing operating performance on a consistent basis across multiple reporting periods by removing the impact of special items, which can vary from period to period, that management does not believe are directly reflective of the Company’s core operations. The Company defines special items as significant non-recurring or non-operational charges or credits, including restructuring charges or credits, gains or losses on the sale of accounts receivable, strike related costs, goodwill and long-lived asset impairments, debt extinguishment charges, pension remeasurement gains and losses, other postretirement/pension curtailment and settlement gains and losses, and gains or losses on sales of businesses.

We define Adjusted EBITDA as net income, excluding net interest expense, income taxes, depreciation and amortization, and special items.

Management believes presenting this non-GAAP financial measure is useful to investors because it (1) provides investors with meaningful supplemental information regarding financial and operating performance by excluding certain items management believes do not directly impact the Company’s core operations, (2) permits investors to view performance using the same metrics that management uses to forecast, evaluate performance, and make operating and strategic decisions, and (3) provides additional information useful to investors on a period-to-period consistent basis that are commonly used to analyze companies’ operating performance. Management believes that consideration of Adjusted EBITDA, together with Net Income, and the corresponding reconciliation, provides investors with additional understanding of the Company’s performance and trends that would be absent such disclosures.

Non-GAAP financial measures should be viewed in addition to, and not superior to or as an alternative for, the Company’s reported results prepared in accordance with GAAP. The following table provides the reconciliation of net income attributable to ATI to the Adjusted EBITDA non-GAAP financial measures:

Earnings before interest, taxes, depreciation and amortization (EBITDA)

Fiscal Year Ended

Net income attributable to ATI $ 404.3 $ 367.8

Net income attributable to noncontrolling interests 14.3 14.9

(+) Depreciation and amortization 168.1 151.5

Adjustments for special items, pre-tax:

(+) Restructuring and other charges (a) 48.8 22.1

(+) Pension settlement loss (b) 18.6 14.1

(+/-) Loss (gain) on sales of businesses (c) 2.9 (52.9)

Adjusted EBITDA as a % of sales 18.7 % 16.7 %

Critical Accounting Policies

The accompanying consolidated financial statements have been prepared in conformity with U.S. GAAP. When more than one accounting principle, or the method of its application, is generally accepted, management selects the principle or method that is most appropriate in our specific circumstances. Application of these accounting principles requires our management to make estimates about the future resolution of existing uncertainties; as a result, actual results could differ from these estimates. In preparing these consolidated financial statements, management has made its best estimates and judgments of the amounts and disclosures included in the financial statements giving due regard to materiality.

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Asset Impairment

We monitor the recoverability of the carrying value of our long-lived assets. An impairment charge is recognized when the expected net undiscounted future cash flows from an asset’s use (including any proceeds from disposition) are less than the asset’s carrying value, and the asset’s carrying value exceeds its fair value. Changes in the expected use of a long-lived asset group, and the financial performance of the long-lived asset group and its operating segment, are evaluated as indicators of possible impairment. Future cash flow value may include appraisals for property, plant and equipment, land and improvements, future cash flow estimates from operating the long-lived assets, and other operating considerations.

Goodwill is reviewed annually in the fourth quarter of each fiscal year for impairment or more frequently if impairment indicators arise. Other events and changes in circumstances may also require goodwill to be tested for impairment between annual measurement dates. At December 28, 2025, the Company had $225.2 million of goodwill on its consolidated balance sheet, all of which relates to the HPMC segment.

We performed quantitative goodwill assessments for the two HPMC reporting units with goodwill during the fourth quarter of fiscal year 2025. Fair values were determined using discounted cash flows, which represents Level 3 unobservable information in the fair value hierarchy. These quantitative assessments and valuations require us to make estimates and assumptions regarding revenue growth, changes in working capital, capital expenditures, selling prices, income taxes, and profitability, all of which impact estimated future cash flows. In addition, discounted cash flow valuations are impacted by the determination of our weighted cost of capital (WACC), which also requires us to exercise judgment and make estimates. Although we believe that the estimates and assumptions used were reasonable, actual results could differ from those estimates and assumptions. For example, the WACC utilized in our discounted cash flow assessments was 10.5% and long-term growth rates ranged from 3% to 3.5%. The estimated effect of a 1% change in the WACC would result in a 15% change in the fair value of the Specialty Materials reporting unit and less than a 2% change in the fair value of the Forged Products reporting unit.

Further, to validate the reasonableness of the estimated fair values of the reporting units as of the valuation date, a reconciliation of the aggregate fair values of all reporting units to our market capitalization is performed, taking into account a reasonable control premium.

The $225.2 million of goodwill remaining as of December 28, 2025 on our consolidated balance sheet is comprised of $159.2 million at the Forged Products reporting unit and $66.0 million at the Specialty Materials reporting unit. The goodwill impairment assessment performed in the fourth quarter of fiscal year 2025 determined that our Specialty Materials and Forged Products reporting units' had fair values in excess of their respective carrying values. As a result, no impairments were determined to exist. In addition, no indicators of impairment were observed in fiscal year 2025 associated with any of our long-lived assets.

Income Taxes