ATI US Equity☆

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.

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 & 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

9

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.

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. Additionally, a significant downturn or deterioration in the business or financial condition or loss of a key customer could negatively impact our business. Our customers may 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 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 part of the increased cost of the raw materials. We source some of these 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. 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 nickel, hafnium, titanium sponge, cobalt, chromium, and 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

10

an adequate supply of these critical supplies on a timely basis, on price and other terms acceptable to us, or at all. If suppliers increase the price of these items, we may not have alternative sources of supply. 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 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 and may continue to adversely affect our profitability. 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.

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 7,700 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

11

results. There can be no assurance that we will succeed in obtaining CBAs to replace those that expire. The Company is currently renegotiating CBAs, which expire on February 28, 2025, that cover approximately 1,100 USW-represented full-time employees within our AA&S operations. There can be no assurance that the Company will successfully conclude these renegotiations to replace the expiring CBAs.

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.

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, and remediation costs, 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 increased 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. Increased 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

12

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 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 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. We also could be subject to future laws and regulations that govern greenhouse gas emissions and various matters related to climate change and other air emissions, which could increase our operating costs. 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 41 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, the potential loss exposure with respect to 14 individual sites is not considered to be material, and the potential loss exposure on the remaining 8 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 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 loss or range of loss. 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 29, 2024, 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.

13

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, health pandemics, 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.

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 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, 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, although 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.

14

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. 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. 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 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.

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.

15

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 29, 2024, our total consolidated indebtedness was approximately $1.9 billion. We also had the ability to borrow approximately $525 million under our Asset Based Lending (ABL) credit facility as of December 29, 2024. 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 rate of return on pension plan assets and other actuarial assumptions, we do not expect to have any significant minimum cash funding requirements to our pension plan for at least ten years. 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 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.

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 2024 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.

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.

16

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 20 years and 14 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 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-

17

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 operational or financial impact as a result of any cybersecurity incident or the cybersecurity risk that we face, and 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 our HPMC segment include melting operations and production facilities that perform processing and finishing operations. 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, East Hartford, CT, and Irvine, CA. Metal alloy-based additive manufacturing for the aerospace & defense industries takes place in our leased facility in Fort Lauderdale, Florida.

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, Washington, Rochester, Monaca, and Zelienople, PA. Additionally, the AA&S segment will benefit from the expanded capabilities at our new Pageland, SC location. Substantially all of our properties are owned.

We own or lease facilities, primarily sales and administrative offices, in a number of foreign countries, including France, Germany, the U.K., Poland, 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.

Our corporate headquarters in Dallas, TX and employee 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

18

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 on January 27, 2025. 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.

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 31, 2025, there were 1,660 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 2024, 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.

19

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 December 29, 2019 through December 29, 2024, 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 December 29, 2019. 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

Certain statements contained in this Management’s Discussion and Analysis of Financial Condition and Results of Operations 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. Net income and net income per share amounts referenced below are attributable to ATI Inc. and Subsidiaries. The following discussion on the Company’s results of operations, financial condition and liquidity for the year ended December 29, 2024 (fiscal year 2024) as compared to the year ended December 31, 2023 (fiscal year 2023) is presented. Information on the Company’s results of operations, financial condition and liquidity for fiscal year 2023 as compared to the year ended January 1, 2023 (fiscal year 2022) 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 23, 2024 and is incorporated herein by reference.

ATI Overview

ATI is a global manufacturer of technically advanced specialty materials and complex components. Our largest markets are aerospace & defense, representing approximately 62% of total sales, led by products for jet engines and airframes. Additionally, we have a strong presence in our other core markets consisting of the specialty energy, medical and electronics markets. In aggregate, these core end markets represent almost 80% of our revenue. ATI is a market leader in manufacturing differentiated products that require our materials science capabilities and unique process technologies, including our new product development competence.

We operate in two business segments: HPMC and AA&S. The HPMC segment’s primary focus is on maximizing jet engine materials and components growth, with approximately 86% of its revenue derived from the aerospace & defense markets including nearly 60% of its revenue 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 growth in defense products, which comprise almost 10% of

20

total sales. Other core markets include medical and specialty energy. 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 final production of highly engineered finished components, and 3D-printed aerospace products.

The AA&S segment is focused on delivering high-value flat products, with a focus on aerospace & defense and other core markets, which comprise approximately 60% of its revenue. Industrial markets comprise the remaining 40% of AA&S sales, which includes the conventional energy and automotive end-markets. AA&S produces nickel-based alloys, titanium and titanium-based alloys, and specialty alloys in a variety of forms including plate, sheet, and strip products.

Overview of Fiscal Year 2024 Financial Performance

Sales in fiscal year 2024 increased 5%, to $4.4 billion, and gross profit increased 12%, to $898 million, compared to fiscal year 2023, reflecting increased demand for products within our aerospace & defense and other core markets of medical, electronics, and specialty energy, which was partially offset by softness in industrial end markets. International sales, including both U.S. exports and foreign sales from our foreign manufacturing operations, were $1.8 billion in fiscal year 2024 and represented 42% of total sales, compared to $1.9 billion or 46% of total sales in fiscal year 2023.

Results for fiscal year 2024 included $17 million of net pre-tax gains and fiscal year 2023 included $104 million of net pre-tax charges as further described in the Results of Operations section below. The Company’s net income for fiscal year 2024 was $367.8 million, or $2.55 per share. ATI Adjusted EBITDA for fiscal year 2024 was $729.1 million, or 16.7% of sales, compared to $634.6 million, or 15.2% of sales, for fiscal year 2023. 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) 2024 2023

Gross profit % of sales 20.6 % 19.2 %

Income before income taxes $ 486.1 $ 295.2

Net income attributable to ATI $ 367.8 $ 410.8

Diluted net income attributable to ATI per common share $ 2.55 $ 2.81

Our major accomplishments during fiscal year 2024 include the following:

•Year-over-year sales growth of approximately 5%, with ATI’s 2024 sales representing our highest total since 2012. Fiscal year 2024 sales to the aerospace & defense markets increased 10% and represent 62% of our total sales, compared to 59% of total sales in fiscal year 2023. We achieved 15% year-over-year sales growth in our other core markets, including increases of 27% and 22% in the medical and electronics markets, respectively. Sales to our aerospace & defense and other core markets increased 11% compared to fiscal year 2023.

•Growth in the aerospace & defense and other core markets drove higher adjusted EBITDA, which improved by 15%, and to 16.7% as a percentage of sales, a 150 basis point improvement compared to 2023, reflecting robust demand that we expect will continue in 2025.

•We generated cash flow of $407.2 million from operating activities in fiscal year 2024 as we continued efforts to focus on operational improvements to positively impact the inventory intensity of our business and alleviate the required investment of managed working capital in our growing business. Managed working capital as a percent of sales was 30.9% as of December 29, 2024, compared to 31.0% as of December 31, 2023, despite an increase in 2024 sales of 5%. We ended the year with $721 million of cash on hand and $1.3 billion of total liquidity including the undrawn capacity under our ABL credit facility.

•We completed the sale of non-core assets, including our precision rolled strip operations in New Bedford, MA and Remscheid, Germany, generating approximately $65 million in proceeds that will be redeployed to support our strategy to improve operational efficiency.

•In 2024, we continued to return cash to our shareholders through the repurchase of our stock. We repurchased 5.3 million shares of ATI stock for $260 million, using all the remaining $150 million under the plan approved by our Board of Directors in November 2023 and $110 million under the $700 million plan approved in 2024.

21

•We made progress in deleveraging our balance sheet. During the third quarter of 2024, we redeemed the $291.4 million outstanding principal amount of ATI’s 3.5% Convertible Senior Notes due 2025 (2025 Convertible Notes) by issuing 18.8 million shares of ATI stock. In addition, we received cash proceeds of $76 million to settle the capped call associated with these notes.

Results of Operations

Fiscal Year 2024 Compared to Fiscal Year 2023

Fiscal year 2024 sales increased $188.4 million to $4.4 billion compared to fiscal year 2023, primarily due to increased demand for next generation commercial engine products and for defense applications and commercial airframes. This increase in sales to the aerospace & defense markets was complemented by an increase in sales across our other core markets, primarily for the medical and electronics end markets. These increases were partially offset by softness in certain industrial markets, particularly the conventional energy market.

Our gross profit was $898.2 million, or 20.6% of sales, a $96 million increase compared to fiscal year 2023. Gross profit in fiscal year 2024 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. Gross profit in fiscal years 2024 and 2023 was also favorably impacted by tax credits of $22.7 million and $10.1 million, respectively. These tax credits were recognized as a reduction in cost of sales by our AA&S segment and are the result of the Advanced Manufacturing Production Credit (AMPC) that was part of the Inflationary Reduction Act of 2022. Operating income was $608.9 million for fiscal year 2024, compared to $466.4 million for fiscal year 2023.

Results for fiscal year 2024 included $16.7 million of net pre-tax benefits, which consisted of the following:

•$52.9 million gain on the sale during the fourth quarter of 2024 of our precision rolled strip operations in New Bedford, MA, which was part of the Specialty-Rolled Products business in the AA&S segment, and Remscheid, Germany, which was part of our European business in the HPMC segment. In fiscal year 2023, these operations had external sales of approximately $100 million and income before tax of approximately $6 million.

•$22.1 million of restructuring and other charges, consisting of $11.3 million of start-up costs, $4.6 million of charges for the restructuring of our European operations, $4.1 million for severance-related restructuring charges primarily for cost reduction actions in our domestic operations and $2.1 million of transaction costs.

•$14.1 million of pension remeasurement losses for the immediate recognition of actuarial losses from the remeasurement of the projected benefit obligation and plan assets for defined benefit pension plans in the fourth quarter of fiscal year 2024.

Results for fiscal year 2023 included $104.3 million of net pre-tax charges, which consisted of the following:

•$0.6 million loss on the sale of our Northbrook, IL operations.

•$35.2 million of restructuring and other charges, consisting of $11.5 million of start-up costs, $14.1 million primarily for asset write-offs associated with the restructuring of our European operations and the closure of our Robinson, PA operations, $1.9 million of costs associated with an unplanned outage at our Lockport, NY melt facility, and $7.7 million of severance-related charges primarily for the restructuring of our European operations and involuntary reductions across ATI’s domestic operations.

•$41.7 million pension settlement loss associated with actions taken as part of our pension derisking strategy. On October 17, 2023, we completed a voluntary cash out for term vested employees and annuity buyouts covering 8,200 U.S. qualified defined benefit pension plan participants.

•$26.8 million of pension remeasurement losses for the immediate recognition of actuarial losses from the remeasurement of the projected benefit obligation and plan assets for defined benefit pension plans in the fourth quarter of fiscal year 2023.

The items discussed above are included in operating income on the consolidated statements of operations, with the exception of the pension related gains and losses in fiscal years 2024 and 2023. Further, the items discussed above are excluded from segment EBITDA.

Fiscal year 2024 results also include charges of $11.8 million, primarily reported in selling & administrative expenses and 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.

Nonoperating retirement benefit expense was $29.0 million, inclusive of a $14.1 million pension remeasurement loss, in fiscal year 2024, compared to $79.7 million in the prior year, inclusive of a $26.8 million pension remeasurement loss. Fiscal year

22

2023 also includes a $41.7 million pension settlement loss, as discussed above. Interest expense increased to $108.2 million in fiscal year 2024 compared to $92.8 million in fiscal year 2023 largely due to the issuance in August 2023 of the $425 million aggregate principal amount of 7.25% Senior Notes due 2030 (2030 Notes), partially offset by the redemption of the 2025 Convertible Notes during the third quarter of 2024. Other nonoperating income for fiscal year 2024 includes a $11.6 million gain on the sale of certain oil and gas rights.

Our effective tax rate was 21.3%, resulting in an income tax provision of $103.4 million for the fiscal year 2024. The effective tax rate for fiscal year 2024 includes discrete tax benefits of $6.2 million inclusive of $3.3 million for share-based compensation. Results in fiscal year 2023 include an income tax benefit of $128.2 million, which included a $140.3 million benefit for the reversal of valuation allowances. Net income attributable to ATI was $367.8 million, or $2.55 per share, in fiscal year 2024, compared to $410.8 million, or $2.81 per share, for fiscal year 2023.

Adjusted EBITDA was $729.1 million, or 16.7% of sales, for fiscal year 2024, and $634.6 million, or 15.2% of sales, for fiscal year 2023. EBITDA and Adjusted EBITDA are measures utilized by ATI that we believe are useful to investors because these measures are commonly used to analyze companies on the basis of operating performance, leverage and liquidity. Furthermore, analogous measures are used by industry analysts to evaluate operating performance. EBITDA and Adjusted EBITDA 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. generally accepted accounting principles (U.S. GAAP). We define EBITDA as income from continuing operations before interest and income taxes, plus depreciation and amortization, goodwill impairment charges and debt extinguishment charges. We define Adjusted EBITDA as EBITDA excluding significant non-recurring charges or credits, restructuring and other charges/credits, gains or losses from the sale of accounts receivables, strike related costs, long-lived asset impairments, pension remeasurement gains and losses, other postretirement/pension curtailment and settlement gains and losses, and gains or losses on sales of businesses. EBITDA and Adjusted EBITDA are not intended to be measures of free cash flow for management’s discretionary use, as they do not consider certain cash requirements such as interest payments, tax payments and capital expenditures. See the Financial Condition and Liquidity section of Management’s Discussion and Analysis for a reconciliation of amounts reported under U.S. GAAP to these non-GAAP measures.

23

Results by Business Segment

As discussed above, we operate in two business segments: HPMC and AA&S. HPMC sales increased 8% in fiscal year 2024 compared to fiscal year 2023, primarily due to higher aerospace & defense market sales. Increased demand for next generation commercial jet engines, defense applications, and commercial airframe products resulted in a 10% increase in sales to the aerospace & defense markets. Full fiscal year 2024 AA&S sales increased 2% due to an 11% increase in aerospace & defense sales, a 47% increase in medical market sales and a 22% increase in electronics market sales partially offset by continued softness in certain general industrial end markets, particularly conventional energy.

Total segment EBITDA was $782.3 million, or 17.9% of sales, in fiscal year 2024, compared to total segment EBITDA of $710.2 million, or 17.0% of sales, in fiscal year 2023. 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, goodwill impairment charges, debt extinguishment charges, corporate expenses, closed operations and other income (expense), restructuring and other credits/charges, gains or losses from the sale of accounts receivables, strike related costs, long-lived asset impairments, pension remeasurement gains and losses, other postretirement/pension curtailment and settlement gains and losses, and gains or losses on sales of businesses. Results on our management basis of reporting were as follows:

(In millions) Fiscal Year Ended

December 29, December 31, January 1,

Sales:

EBITDA:

High Performance Materials & Components $ 461.4 $ 433.6 $ 303.4

Closed operations and other income (expenses) 10.8 (13.3) (5.6)

Restructuring and other charges (22.1) (31.4) (23.7)

Retirement benefit settlement loss — (41.7) —

Pension remeasurement gain (loss) (14.1) (26.8) 100.3

Joint venture restructuring credit — — 0.9

Gains (losses) on sale of businesses, net 52.9 (0.6) (105.4)

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

24

Managed Working Capital performance as a percentage of the prior three months’ annualized sales to evaluate the asset intensity of our business.

At December 29, 2024, Managed Working Capital was 30.9% of annualized total ATI sales compared to 31.1% of annualized sales at December 31, 2023. Although overall Managed Working Capital increased year over year primarily due to increases in inventory and accounts receivable, such increases were largely in line and due to our increased sales given our fairly consistent Managed Working Capital as a percentage of annualized sales year over year. The $129.4 million increase in overall Managed Working Capital in fiscal year 2024 is detailed in the table below. Days sales outstanding, which measures actual collection timing for accounts receivable, worsened slightly by 2% as of December 29, 2024 compared to fiscal year 2023. Gross inventory turns, which measures how many times we turn over our inventory relative to cost of sales in a year, was consistent in fiscal year 2024 compared to fiscal year 2023. We continue efforts to focus on operational improvements to positively impact the inventory intensity of our business and alleviate the required investment of Managed Working Capital in our growing business.

The computations of Managed Working Capital at December 29, 2024 and December 31, 2023 reconciled to the financial statement line items as computed under U.S. GAAP, were as follows.

Short-term contract assets 75.6 59.1

Short-term contract liabilities (169.4) (163.6)

Allowance for doubtful accounts 15.0 3.2

Net managed working capital held for sale 8.5 —

Managed working capital as a % of annualized sales 30.9 % 31.1 %

December 29, 2024 change in managed working capital $ 129.4

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:

25

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 45 % 49 %

Precision forgings, castings and components 19 % 17 %

Titanium and titanium-based alloys 18 % 17 %

PRS products 9 % 10 %

Zirconium and related alloys 9 % 7 %

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

(In millions) Fiscal Year

Information with respect to our business segments follows.

High Performance Materials & Components

Fiscal Year Fiscal Year

Segment EBITDA as a percentage of sales 20.3 % 20.5 %

International sales as a percentage of sales 50.2 % 56.8 %

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 2024 Compared to Fiscal Year 2023

Sales of $2.3 billion for the HPMC segment in fiscal year 2024 increased 8% compared to fiscal year 2023, primarily due to strong demand in aerospace & defense markets as well as increased medical market sales, which were up 13% compared to fiscal year 2023. Sales to the commercial aerospace market increased 8%, as airframe sales increased 5% and commercial jet engine sales increased 9%, and sales to the defense market increased 24%. Industrial markets sales declined by 23%.

26

Comparative information for our HPMC segment revenues by market, the respective percentages of overall segment revenues for the fiscal years 2024 and 2023, and the percentage change in revenues by market for fiscal year 2024 is as follows:

(In millions) Fiscal Year

Aerospace & Defense:

Electronics 3.0 — % 3.1 — % (0.1) (3) %

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, parts and components 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 opportunity 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 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 approximately 30,000 jet engines with firm orders (Aero Engine News, January 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.

27

As the number of aircraft in service increases, the need for our materials associated with engine refurbishment is expected to increase.

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 41 % 44 %

Precision forgings, castings and components 36 % 33 %

Titanium and titanium-based alloys 23 % 22 %

PRS products — % 1 %

HPMC segment EBITDA for fiscal year 2024 increased 6% to $461.4 million, or 20.3% of sales, compared to $433.6 million, or 20.5% of sales, in fiscal year 2023. Strength in the HPMC segment continues to be driven by increased volumes on higher margin next-generation commercial aerospace platforms. 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. Fiscal year 2023 included a $10.5 million benefit associated with an insurance claim due to an outage at one of our facilities.

Advanced Alloys & Solutions

Fiscal Year Fiscal Year

Segment EBITDA as a percentage of sales 15.4 % 13.5 %

International sales as a percentage of sales 33.2 % 35.0 %

Fiscal Year 2024 Compared to Fiscal Year 2023

Sales of $2.1 billion for the AA&S segment in fiscal year 2024 increased 2% compared to fiscal year 2023, as an 11% increase in aerospace & defense sales, a 47% increase in medical market sales and a 22% increase in electronics market sales were partially offset by continued industrial markets softness, particularly conventional energy.

28

Comparative information for our AA&S segment revenues by market, the respective percentages of overall segment revenues, for the fiscal years 2024 and 2023, and the percentage change in revenues by market for fiscal year 2024 is as follows:

(In millions) Fiscal Year

Aerospace & Defense:

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 49 % 54 %

PRS products 19 % 19 %

Zirconium and related alloys 19 % 15 %

Titanium and titanium-based alloys 13 % 12 %

Segment EBITDA was $320.9 million, or 15.4% of sales, a 16% increase from segment EBITDA of $276.6 million, or 13.5% of sales, in fiscal year 2023. The margin increase compared to the prior year was primarily due to a favorable sales mix, as growth in titanium mill products and exotic alloys offset weaker demand for nickel-based alloys. AA&S segment EBITDA in fiscal year 2024 and 2023 included benefits from credits of $22.7 million and $10.1 million, respectively, for the AMPC. 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.

29

Corporate Expenses

Corporate expenses, which are primarily included in selling and administrative expenses in the statement of operations, were $64.0 million in fiscal year 2024 compared to $62.3 million in fiscal year 2023. Increased expenses in fiscal years 2024 compared to fiscal year 2023 were primarily due to higher incentive compensation costs.

Closed Operations and Other Income/Expenses

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 $10.8 million in fiscal year 2024, compared to expense of $13.3 million in fiscal year 2023. 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, and favorable foreign currency transaction impacts as compared to the prior year period. 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. We received $3.5 million of proceeds from this sale, which was reported as an investing activity on the consolidated statement of cash flows. Fiscal year 2023 reflects higher insurance costs associated with an outstanding insurance claim involving our captive insurance company.

Depreciation and Amortization

The following table shows depreciation & amortization for the relevant periods by each business segment. Depreciation expense in fiscal year 2023 includes $3.8 million of accelerated depreciation of fixed assets related to the restructuring of our European operations and the closure of our Robinson, PA operations.

Fiscal Year

Depreciation and amortization:

High Performance Materials & Components $ 71.6 $ 71.1

Advanced Alloys & Solutions 73.2 67.9

Interest Expense, Net

Interest expense, net of interest income and interest capitalization, was $108.2 million in fiscal year 2024, compared to $92.8 million in fiscal year 2023. The increase in fiscal year 2024 compared to fiscal year 2023 is largely a result of the issuance in August 2023 of the 2030 Notes, partially offset by a decline from the redemption of the 2025 Convertible Notes during the third quarter of 2024. Further, interest expense is presented net of interest income of $16.0 million in fiscal year 2024 and $13.0 million in fiscal year 2023. Interest expense in fiscal years 2024 and 2023 was reduced by $11.8 million and $13.5 million, respectively, related to interest capitalization on large, strategic capital projects.

Restructuring and Other Charges/Credits

For the fiscal year ended December 29, 2024, restructuring and other charges were $22.1 million and include $11.3 million of start-up costs, $4.6 million of charges associated with our European restructuring, $4.1 million of severance-related restructuring charges primarily related to cost reduction actions in our domestic operation, and $2.1 million of transaction related costs. These costs were recorded in the consolidated statement of operations based on the nature of the charge, with $15.3 million recorded as cost of sales, $2.7 million recorded as selling and administrative expenses and $4.1 million as restructuring charges on the consolidated statements of operations. These restructuring and other charges are excluded from segment and adjusted EBITDA.

For the fiscal year ended December 31, 2023, restructuring and other charges were $31.4 million, which are excluded from segment results. These charges include $7.7 million of severance-related restructuring charges and $23.7 million of charges included within cost of sales on the consolidated statements of operations. The $7.7 million of severance-related restructuring charges represent severance for our European restructuring and headcount reductions in ATI domestic operations. The $23.7 million of charges within cost of sales include $11.5 million of start-up costs, $1.9 million of costs associated with an unplanned outage at our Lockport, NY facility, and $10.3 million primarily for asset write-offs for the restructuring of our

30

European operations and the closure of our Robinson, PA operations. These restructuring and other charges are excluded from segment and adjusted EBITDA.

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 $14.1 million and $26.8 million in fiscal years 2024 and 2023, respectively. These losses are excluded from segment and adjusted EBITDA and recorded in nonoperating retirement benefit income/expense on the consolidated statements of operations.

Retirement Benefit Settlement Gains and Losses

On October 17, 2023, we completed a voluntary cash out for term vested employees and a large annuity buyout related to approximately 8,200 U.S. qualified defined benefit pension plan participants. As a result of the annuity buyout, ATI recognized a $41.7 million pretax settlement loss, which is excluded from segment and adjusted EBITDA and recorded in nonoperating retirement benefit income/expense on the consolidated statement of operations.

Gains/Loss on Sale of Businesses, Net

Gain on sales of businesses for fiscal year 2024 is related to a $52.9 million gain on the sale of our precision rolled strip operations in New Bedford, MA operations and Remscheid, Germany, for which $48.0 million of proceeds, net of transaction costs, were received and reported as an investing activity on the consolidated statement of cash flows.

Loss on sales of businesses for fiscal year 2023 is related to a $0.6 million loss on the sale of our Northbrook, IL operations. These gains and losses on sale of businesses are excluded from segment and adjusted EBITDA.

Income Taxes

For fiscal year 2024, our effective tax rate was 21.3% resulting in an income tax provision of $103.4 million. The effective tax rate for fiscal year 2024 includes discrete tax benefits of $6.2 million inclusive of $3.3 million for share-based compensation. Results in fiscal year 2023 include an income tax benefit of $128.2 million, which included a $140.3 million benefit for the reversal of valuation allowances.

Financial Condition and Liquidity

We have an ABL credit facility, which is collateralized by the accounts receivable and inventory of our operations. The ABL credit facility also provides us with the option of including certain machinery and equipment as additional collateral for purposes of determining availability under the facility. The ABL credit facility, which matures in September 2027, includes a $600 million revolving credit facility, a letter of credit sub-facility of up to $200 million, a $200 million term loan (ABL Term Loan), and a swing loan facility of up to $60 million. The ABL 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 29, 2024, there were no outstanding borrowings under the revolving credit portion of the ABL, and $30.5 million was utilized to support the issuance of letters of credit. There were no revolving credit borrowings under the ABL during fiscal year 2024. There were average revolving credit borrowings of $13 million bearing an average annual interest rate of 6.5% under the ABL during fiscal year 2023.

The ABL Term Loan has an interest rate of 2.0% above 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 29, 2024.

31

During the fourth quarter of 2024, we received $48.0 million in cash, net of transaction costs, for the sale of our precision rolled strip operations in New Bedford, MA and Remscheid, Germany. We also received $11.6 million in cash for the sale of certain oil and gas rights. Overall, we received cash for non-core assets sales of over $65 million, which are recorded in investing activities on the consolidated statement of cash flows.

During the third quarter of 2024, we notified holders of the $291.4 million outstanding principal amount of our 2025 Convertible Notes that they would be redeemed prior to their maturity date. The holders of any outstanding 2025 Convertible Notes had the right to convert the principal amount of such notes into shares of ATI’s common stock prior to the maturity date. Any 2025 Convertible Notes not tendered for conversion prior to the maturity date were redeemed in cash at a redemption price equal to the principal amount, plus accrued and unpaid interest. As a result, $291.0 million principal amount of the outstanding notes was converted to 18.8 million shares of ATI common stock, with the remaining $0.4 million of outstanding principal balance that was not tendered for conversion paid in cash. We also settled the capped call transactions initiated as part of the issuance of the 2025 Convertible Notes for $76.1 million in cash, which is recorded as additional paid-in capital on the consolidated balance sheet and as a financing activity on the consolidated statement of cash flows.

At December 29, 2024, we had $721 million of cash and cash equivalents, and available additional liquidity from the undrawn capacity under the ABL credit facility of approximately $525 million, for total liquidity of approximately $1.3 billion. Our next meaningful debt maturity is $150 million of debentures in the fourth quarter of fiscal year 2025, which we expect to repay with cash on hand at that time.

In October 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. After these actions, our U.S. qualified defined benefit plan includes approximately 2,000 participants. Based on current actuarial assumptions, we are not required to make any contributions to our pension plan during fiscal year 2025. Using our long-term weighted average expected rate of return on pension plan assets and other actuarial assumptions, we do not expect to have any significant minimum cash funding requirements to the defined benefit pension plan for at least ten years. However, these funding estimates are subject to significant uncertainty including the actual pension trust assets’ fair value, 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 2024, ATI used $260 million to repurchase 5.3 million shares of its common stock under the Share Repurchase Program. As of December 29, 2024, there is $590 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.

32

Our Debt to Adjusted EBITDA Leverage Ratio and Net Debt to Adjusted EBITDA Leverage ratio improved in fiscal year 2024 compared to fiscal year 2023, resulting from higher earnings and lower debt as a result of the redemption of the 2025 Convertible Notes. 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:

Net income attributable to ATI $ 367.8 $ 410.8

Net income attributable to noncontrolling interests 14.9 12.6

Depreciation and amortization 151.5 146.1

Income tax provision (benefit) 103.4 (128.2)

Pension remeasurement loss 14.1 26.8

Retirement benefit settlement loss — 41.7

Restructuring and other charges 22.1 31.4

Loss (gain) on asset sales and sale of business (52.9) 0.6

Add: Debt issuance costs 14.2 19.6

Debt to Adjusted EBITDA 2.62 3.47

Net Debt to Adjusted EBITDA 1.63 2.29

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 2025. 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 29, 2024, 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 $407.2 million for fiscal year 2024 and $85.9 million fiscal year 2023, which included $272 million in contributions to the U.S. defined benefit pension plans. Both periods reflect higher accounts receivable and higher inventory balances due to increased operating levels, but these conditions impacted 2024 to a much lesser extent than 2023. 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 2024 operating cash flow items included payment of 2023 annual incentive compensation. Other significant fiscal year 2023 operating cash flow items included payment of 2022 annual incentive compensation.

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 core markets, including 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. 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 $193.2 million in fiscal year 2023, reflecting $200.7 million in capital expenditures primarily related to AA&S transformation projects and various HPMC growth projects.

33

Cash used by financing activities in fiscal year 2024 was $260.4 million, which included $260.0 million to repurchase 5.3 million shares of 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. Cash provided by financing activities in fiscal year 2023 was $267.2 million, and included $418.8 million of net proceeds from the issuance of the 2030 Notes during the third quarter of fiscal year 2023, partially offset by $85.2 million toward the repurchase of 2.0 million shares of ATI stock under our repurchase programs authorized by our Board of Directors and $16.0 million in dividend payments to the 40% noncontrolling interest in our PRS joint venture in China.

At December 29, 2024, cash and cash equivalents on hand totaled $721.2 million, a $22.7 million increase from fiscal year-end 2023. Cash and cash equivalents held by our foreign subsidiaries was $210.8 million at December 29, 2024, of which $100.9 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

Capital expenditures 32.0 32.0 — — —

Other Financial Commitments

Guarantees $ 16.8

(A)Amounts exclude $95 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 29, 2024 applicable to the Company’s ABL Term Loan due 2027, the Allegheny Ludlum 6.95% Debentures due 2025, the 2027 Notes, the 2029 Notes, the 2030 Notes and the 2031 Notes.

(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 29, 2024, for raw material obligations with variable pricing.

(F)We have various contractual obligations that extend through fiscal year 2030 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.

34

(G)At December 29, 2024, drawn amounts on the U.S. facility were $30.5 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: $20.8 million in workers’ compensation and general insurance arrangements, $5.4 million related to environmental matters and $4.3 million for performance assurances.

Commitments and Contingencies

At December 29, 2024, our reserves for environmental remediation obligations totaled approximately $15 million, of which $6 million was included in other current liabilities. These reserves included estimated probable future costs of: $3 million for federal Superfund and comparable state-managed sites; $6 million for formerly owned or operated sites for remediation or indemnification obligations; $5 million for owned or controlled sites at which our operations have been or plan to be discontinued; and $1 million for sites utilized by the Company in its ongoing operations. 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) recording by the Company were $8 million at December 29, 2024. 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 de-recognized $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

All of 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 800 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 during this period 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 29, 2024, our defined benefit pension plans were approximately 92% funded in accordance with generally accepted accounting principles, and were remeasured at that date using a 5.85% discount rate to measure the projected benefit obligation. For ERISA funding purposes, discount rates used to measure pension liabilities for U.S. qualified defined benefit plans 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 not required to make any contributions to our pension plan during fiscal year 2025, and will not be required to make significant contributions for at least ten years. 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.

Critical Accounting Policies

The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles. 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

35

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.

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.

As of April 3, 2022, our Sheffield, U.K. operations were classified as held for sale, and the terms of sale resulted in indicators of impairment in the long-lived assets of this disposal group. A $22.3 million long-lived asset impairment charge was recorded in the first quarter of fiscal year 2022, reported as part of the $112.2 million loss on sale of this business for the fiscal year ended January 1, 2023. This long-lived asset impairment charge was determined using the held for sale framework and represents Level 1 information in the fair value hierarchy.

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 29, 2024, the Company had $227.2 million of goodwill on its consolidated balance sheet, all of which relates to the HPMC segment.

For our annual goodwill impairment evaluation performed in the fourth quarter of fiscal year 2024, quantitative goodwill assessments were performed for the two HPMC reporting units with goodwill. Fair values were determined by using a quantitative assessment that includes discounted cash flow and multiples of cash earnings valuation techniques, plus valuation comparisons to recent public sale transactions of similar businesses, if any, which represents Level 3 unobservable information in the fair value hierarchy. These impairment assessments and valuation methods require us to make estimates and assumptions regarding revenue growth, changes in working capital and capital expenditures, selling prices and profitability that drive cash flows, and the WACC. Many of these assumptions are determined by reference to market participants we have identified. For example, our WACC used in our discounted cash flow assessments was 11.0% and long-term growth rates ranged from 3% to 3.5%. The estimated effect of a 0.50% change in the WACC would result in a 7% change in the fair value of the Forged Products reporting unit. Although we believe that the estimates and assumptions used were reasonable, actual results could differ from those estimates and assumptions.

The $227.2 million of goodwill remaining as of December 29, 2024 on our consolidated balance sheet is comprised of $161.2 million at the Forged Products reporting unit and $66.0 million at the Specialty Materials reporting unit. For our annual goodwill impairment evaluation performed in the fourth quarter of fiscal year 2024, the Specialty Materials reporting unit had a fair value that was significantly in excess of carrying value. The Forged Products reporting unit had a fair value that exceeded carrying value by approximately 95% for the fiscal year 2024 annual assessment, which increased compared to the annual evaluation for fiscal year 2023. As a result, no impairments were determined to exist from the annual goodwill impairment evaluation for the fiscal years ended December 29, 2024, December 31, 2023 or January 1, 2023. In order 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 market capitalization was performed using a reasonable control premium. In addition, no indicators of impairment were observed in fiscal years 2024 or 2023 associated with any of our long-lived assets.

Income Taxes

The provision for income taxes includes deferred taxes resulting from temporary differences in income for financial and tax purposes using the liability method. Such temporary differences result primarily from differences in the carrying value of assets and liabilities. Future realization of deferred income tax assets requires sufficient taxable income within the carryback and/or carryforward period available under tax law. On a quarterly basis, we evaluate the realizability of our deferred tax assets.

The evaluation includes the consideration of all available evidence, both positive and negative, regarding the estimated future reversals of existing taxable temporary differences, estimated future taxable income exclusive of reversing temporary differences and carryforwards, historical taxable income in prior carryback periods if carryback is permitted, and potential tax planning strategies which may be employed to prevent an operating loss or tax credit carryforward from expiring unused. In situations where a three-year cumulative loss condition exists, accounting standards limit the ability to consider projections of future results as positive evidence to assess the realizability of deferred tax assets. Valuation allowances are established when it is estimated that it is more likely than not that the tax benefit of the deferred tax asset will not be realized.

36

At the end of fiscal year 2023, ATI’s U.S. operations exited a three-year cumulative loss position, which previously limited the ability to utilize future projections as verifiable sources of income when analyzing the need for a valuation allowance. As part of the exit, we concluded it was appropriate to consider future projections as a source of income when analyzing the need for a valuation allowance. With the utilization of projections, we determined that valuation allowances on net deferred tax asset balances for federal and certain state jurisdictions are no longer required. Certain individual tax attributes still require a valuation allowance based on expected utilization. We updated our projections at the end of fiscal year 2024 and determined a deferred tax asset valuation allowance of $57.7 million was still needed. In addition, we have $23.3 million of valuation allowances on amounts recorded in other comprehensive loss on the consolidated balance sheet as of December 29, 2024. Results for fiscal years 2023 and 2022 include impacts from income taxes that differ from applicable standard tax rates, primarily related to income tax valuation allowances on the current year income along with the release of the valuation allowance in fiscal year 2023.

Retirement Benefits

We have defined contribution retirement plans or benefit pension plans covering substantially all of our employees. We also sponsor several postretirement plans covering certain hourly and salaried employees and retirees. These plans provide health care and life insurance benefits for eligible employees. Company contributions to defined contribution retirement plans are generally based on a percentage of eligible pay or based on hours worked, and are funded with cash. All of 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 800 participants still accruing benefit service. Additionally, all of the remaining, collectively bargained defined benefit retiree health care plans at ATI’s operations are 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.

Under U.S. generally accepted accounting principles, amounts recognized in financial statements for defined benefit pension plans are determined on an actuarial basis, rather than as contributions are made to the plan. A significant element in determining our pension income or expense in accordance with the accounting standards is the expected investment return on plan assets. In establishing the expected return on plan investments, which is reviewed annually in the fourth quarter, we take into consideration input from our third-party pension plan asset managers and actuaries regarding the types of securities the plan assets are invested in, how those investments have performed historically, and expectations for how those investments will perform in the future. Our weighted average expected long-term return on pension plan investments was 5.80% in fiscal year 2024. The expected long-term rate of return on pension plan investments for fiscal year 2025 will be 5.80%. We apply the assumed rate of return to the market value of plan assets at the end of the previous year. This produces the expected return on plan assets that is included in annual pension expense for the current year. The actual returns on pension plan assets for the last five fiscal years have been (2.7)% for 2024, 2.0% for 2023, (14.5)% for 2022, 12.4% for 2021, and 15.2% for 2020. The effect of increasing, or lowering, the expected return on pension plan investments by 0.25% would result in additional pre-tax annual income, or expense, of approximately $1 million. The cumulative difference between the expected return and the actual return on plan assets is immediately recognized in earnings through net periodic pension benefit cost within nonoperating retirement benefit expense on the consolidated statements of operations when pension plans are remeasured annually in the fourth quarter or on an interim basis as triggering events require remeasurement. The amount of expected return on plan assets can vary significantly from year-to-year since the calculation is dependent on the market value of plan assets as of the end of the preceding year. U.S. generally accepted accounting principles allow companies to calculate the expected return on pension assets using either an average of fair market values of pension assets over a period not to exceed five years, which reduces the volatility in reported pension income or expense, or their fair market value at the end of the previous year. However, the U.S. Securities and Exchange Commission currently does not permit companies to change from the fair market value at the end of the previous year methodology, which is the methodology that we use, to an averaging of fair market values of plan assets methodology. As a result, our results of operations and those of other companies, including companies with which we compete, may not be comparable due to these different methodologies in calculating the expected return on pension investments.

In accordance with accounting standards, we determine the discount rate used to value pension plan liabilities as of the last day of our fiscal year. The discount rate reflects the current rate at which the pension liabilities could be effectively settled. In estimating this rate, we receive input from our actuaries regarding the rates of return on high quality, fixed-income investments with maturities matched to the expected future retirement benefit payments. Based on this assessment, we established a discount rate of 5.85% for valuing the pension liabilities as of December 29, 2024, and for determining the pension expense for fiscal year 2025. We had assumed a discount rate of 5.60% at the end of fiscal year 2023, and initially assumed a discount rate of 5.55% at the end of fiscal year 2022, which changed to 6.40% upon the remeasurement as of October 17, 2023, following the large annuity buyout of retirees. The estimated effect of changing the discount rate by 0.50% would decrease pension liabilities in the case of an increase in the discount rate or increase pension liabilities in the case of a decrease in the discount rate, by approximately $20 million. Such a change in the discount rate would have an insignificant impact to pension expense. The effect on pension liabilities for changes to the discount rate, as well as the net effect of other changes in actuarial assumptions

37

and experience, are immediately recognized in earnings through net periodic pension benefit cost within nonoperating retirement benefit expense on the consolidated statements of operations when pension plans are remeasured annually in the fourth quarter or on an interim basis as triggering events require remeasurement. This immediate recognition is in accordance with the accounting standards and is the Company’s accounting policy as discussed in Note 1 to the Consolidated Financial Statements.

With respect to our postretirement plans, under most of the plans, our contributions towards retiree medical premiums are capped based upon the cost as of certain dates, thereby creating a defined contribution. In accordance with U.S. generally accepted accounting standards, postretirement expenses recognized in financial statements associated with defined benefit plans are determined on an actuarial basis, rather than as benefits are paid. We use actuarial assumptions, including the discount rate and the expected trend in health care costs, to estimate the costs and benefit obligations for these plans. The discount rate, which is determined annually at the end of each fiscal year, is developed based upon rates of return on high quality, fixed-income investments. At the end of fiscal year 2024, we determined the rate to be 5.60%, compared to a 5.40% discount rate in fiscal year 2023, and a 5.45% discount rate in fiscal year 2022. The estimated effect of changing the discount rate by 0.50% would decrease postretirement obligations in the case of an increase in the discount rate or increase postretirement obligations in the case of a decrease in the discount rate, by approximately $6 million. Such a change in the discount rate would have an insignificant impact to postretirement benefit expense. Based upon predictions of continued significant medical cost inflation in future years, the annual assumed rate of increase in the per capita cost of covered benefits of health care plans is 6.6% in 2025 and is assumed to gradually decrease to 4.0% in the year 2048 and remain level thereafter. Assumed health care cost trend rates can have a significant effect on the benefit obligation for health care plans, however, the Company’s contributions for most of its retiree health plans are capped based on a fixed premium amount, which limits the impact of future health care cost increases.

Forward-Looking Statements

From time-to-time, the Company has made and may continue to make “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Certain statements in this report relate to future events and expectations and, as such, constitute forward-looking statements. Forward-looking statements include those containing such words as “anticipates,” “believes,” “estimates,” “expects,” “would,” “should,” “will,” “will likely result,” “forecast,” “outlook,” “projects,” and similar expressions. Such forward-looking statements are based on management’s current expectations and include known and unknown risks, uncertainties and other factors, many of which the Company is unable to predict or control, that may cause our actual results or performance to materially differ from any future results or performance expressed or implied by such statements. Various of these factors are described in Item 1A, Risk Factors, of this Annual Report on Form 10-K and will be described from time-to-time in the Company filings with the SEC, including the Company’s Annual Reports on Form 10-K and the Company’s subsequent reports filed with the SEC on Form 10-Q and Form 8-K, which are available on the SEC’s website at www.sec.gov and on the Company’s website at www.atimetals.com. We assume no duty to update our forward-looking statements.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

As part of our risk management strategy, we utilize derivative financial instruments, from time to time, to hedge our exposure to changes in energy and raw material prices, foreign currencies, and interest rates. We monitor the third-party financial institutions that are our counterparty to these financial instruments on a daily basis and diversify our transactions among counterparties to minimize exposure to any one of these entities. Fair values for derivatives were measured using exchange-traded prices for the hedged items including consideration of counterparty risk and ATI’s credit risk. Our exposure to volatility in interest rates is presently not material, as nearly all of our debt is at fixed interest rates.

Volatility of Interest Rates. We may enter into derivative interest rate contracts to maintain a reasonable balance between fixed- and floating-rate debt. ATI previously maintained a $50 million floating-for-fixed interest rate swap which converted a portion of the ABL Term Loan to a 4.21% fixed rate that matured during the quarter ended June 30, 2024. There are no outstanding derivative interest rate contracts at December 29, 2024.

Volatility of Energy Prices. Energy resources markets are subject to conditions that create uncertainty in the prices and availability of energy resources. 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 beyond our control. Increases in energy costs, or changes in costs relative to energy costs paid by competitors, have and may continue to adversely affect our profitability. 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. We use approximately 6 to 8 million MMBtu’s of natural gas annually, depending upon business conditions, in the manufacture of our products. These purchases of natural gas expose us to risk of higher gas prices. For example, a hypothetical $1.00 per MMBtu increase in the price of natural gas would result in increased annual energy costs of approximately $6 to $8 million. We use several

38

approaches to minimize any material adverse effect on our financial condition or results of operations from volatile energy prices. These approaches include incorporating an energy surcharge on many of our products and using financial derivatives or physical hedges to reduce exposure to energy price volatility.

At December 29, 2024, the outstanding financial derivatives used to hedge our exposure to energy cost volatility included natural gas hedges. At December 29, 2024, we hedged approximately 75% of our annual forecasted domestic requirements for natural gas for fiscal year 2025 and approximately 35% for fiscal year 2026. At December 29, 2024, the net mark-to-market valuation of the outstanding natural gas hedges was an unrealized pre-tax loss of $0.1 million, comprised of $0.8 million in prepaid expenses and other current assets, $0.9 million in other long-term assets, $1.7 million in other current liabilities and $0.1 million in other long-term liabilities on the balance sheet. For the year ended December 29, 2024, the effects of natural gas hedging activity increased cost of sales by $8.0 million.

Volatility of Raw Material Prices. We use raw materials surcharge and index mechanisms to offset the impact of increased raw material costs; however, competitive factors in the marketplace can limit our ability to institute such mechanisms, and there can be a delay between the increase in the price of raw materials and the realization of the benefit of such mechanisms. For example, in fiscal year 2024 we used approximately 70 million pounds of nickel; therefore a hypothetical change of $1.00 per pound in nickel prices would result in increased costs of approximately $70 million. While we enter into raw materials futures contracts from time-to-time to hedge exposure to price fluctuations, such as for nickel, 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.

The majority of our products are sold utilizing raw material surcharges and index mechanisms. However, as of December 29, 2024, we had entered into financial hedging arrangements, primarily at the request of our customers, related to firm orders, for an aggregate amount of approximately 4 million pounds of nickel with hedge dates through fiscal year 2027. The aggregate notional amount hedged is approximately 5% of a single year’s estimated nickel raw material purchase requirements. These derivative instruments are used to hedge the variability of a selling price that is based on the London Metals Exchange (LME) index for nickel, as well as to hedge the variability of the purchase cost of nickel based on this LME index. Any gain or loss associated with these hedging arrangements is included in sales or cost of sales, depending on whether the underlying risk being hedged was the variable selling price or the variable raw material cost, respectively. At December 29, 2024, the net mark-to-market valuation of our outstanding raw material hedges was an unrealized pre-tax loss of $4.2 million, comprised of $4.2 million in other current liabilities on the balance sheet.

Foreign Currency Risk. Foreign currency exchange contracts are used, from time-to-time, to limit transactional exposure to changes in currency exchange rates. We sometimes purchase foreign currency forward contracts that permit us to sell specified amounts of foreign currencies expected to be received from our export sales for pre-established U.S. dollar amounts at specified dates. In addition, we may also hedge forecasted capital expenditures and designate cash balances held in foreign currencies as hedges of forecasted foreign currency transactions. At December 29, 2024, we had no significant outstanding foreign currency forward contracts.

We may also use derivative instruments that are not designated as hedges to protect our results from certain fluctuations in foreign exchange rates, as well as to offset a portion of the foreign currency gains and losses generated by the remeasurement of certain assets and liabilities denominated in non-functional currencies. Changes in the fair value of these foreign exchange contract derivatives not designated as hedging instruments are recorded in cost of sales or selling, general and administrative expenses on the consolidated statement of operations, and we recognized $2.2 million of expense, net, for settled foreign currency forward contracts that were not designated as hedges during the fiscal year ended December 29, 2024, which offset foreign currency gains/losses in the relevant currency. We have no significant outstanding hedges that are not designated as of December 29, 2024.

39

Item 8. Financial Statements and Supplementary Data

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of ATI Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of ATI Inc. and subsidiaries (the Company) as of December 29, 2024 and December 31, 2023, the related consolidated statements of operations, comprehensive income, cash flows and statements of changes in consolidated equity for each of the three years in the period ended December 29, 2024, and the related notes (collectively referred to as the “consolidated financial statements”.) In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 29, 2024 and December 31, 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 29, 2024, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 29, 2024, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework), and our report dated February 21, 2025 expressed an unqualified opinion thereon.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

40

Goodwill impairment assessment - Forged Products reporting unit

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 1996.

Pittsburgh, Pennsylvania

February 21, 2025

41

ATI Inc. and Subsidiaries

Consolidated Statements of Operations

(In millions, except per share amounts)

Fiscal Year Ended

Restructuring charges (credits) 4.1 7.7 (4.8)

Loss (gain) on asset sales and sales of businesses, net (57.1) 0.4 105.4

Nonoperating retirement benefit income (expense) (29.0) (79.7) 138.4

Less: Net income attributable to noncontrolling interests 14.9 12.6 15.6

Basic net income attributable to ATI per common share $ 2.82 $ 3.21 $ 2.54

Diluted net income attributable to ATI per common share $ 2.55 $ 2.81 $ 2.23

The accompanying notes are an integral part of these statements.

42

ATI Inc. and Subsidiaries

Consolidated Statements of Comprehensive Income

(In millions)

Fiscal Year Ended

Currency translation adjustment

Unrealized net change arising during the period (13.0) 1.3 (43.5)

Reclassification adjustment included in net income — — 20.0

Derivatives

Net derivatives gain (loss) on hedge transactions (5.9) (28.5) 53.8

Reclassification to net income of net realized loss (gain) 11.0 2.5 (42.8)

Income taxes on derivative transactions 2.0 (6.1) —

Postretirement benefit plans

Actuarial gain/loss

Amortization of net actuarial loss 5.2 6.0 13.2

Net gain (loss) arising during the period (2.2) (3.8) 54.7

Prior service cost

Amortization to net income of net prior service credits (0.5) (0.6) (0.5)

Settlement loss included in net income — 1.1 0.7

Income taxes on postretirement benefit plans 0.5 0.3 —

Other comprehensive income (loss), net of tax (7.9) (16.2) 55.6

Comprehensive income attributable to ATI $ 361.5 $ 395.0 $ 397.4

The accompanying notes are an integral part of these statements.

43

ATI Inc. and Subsidiaries

Consolidated Balance Sheets

Assets

Cash and cash equivalents $ 721.2 $ 743.9

Short-term contract assets 75.6 59.1

Prepaid expenses and other current assets 86.0 62.2

Liabilities and Stockholders’ Equity

Short-term contract liabilities 169.4 163.6

Short-term debt and current portion of long-term debt 180.4 31.9

Accrued postretirement benefits 164.3 175.2

Equity:

ATI Stockholders’ Equity:

Preferred stock, par value $0.10: authorized-50,000,000 shares; issued-none — —

Retained earnings (loss) 64.3 (70.1)

Accumulated other comprehensive loss, net of tax (89.5) (83.2)

Total Liabilities and Stockholders’ Equity $ 5,230.6 $ 4,985.1

The accompanying notes are an integral part of these statements.

44

ATI Inc. and Subsidiaries

Consolidated Statements of Cash Flows

(In millions)

Fiscal Year Ended

Operating Activities:

Gain from disposal of property, plant and equipment, net (15.7) (0.6) (0.9)

Net loss (gain) from sales of businesses (52.9) 0.6 112.2

Non-cash impairment charges — 3.0 —

Change in operating assets and liabilities:

Pension plan contributions — (272.0) (51.3)

Accrued income taxes (0.3) (4.8) 2.5

Accrued liabilities and other (67.1) (26.8) (23.1)

Investing Activities:

Purchases of property, plant and equipment (239.1) (200.7) (130.9)

Proceeds from disposal of property, plant and equipment 27.6 3.8 3.1

Proceeds from sales of businesses, net of transaction costs 48.0 (0.3) 0.3

Financing Activities:

Borrowings on long-term debt — 425.0 —

Payments on long-term debt and finance leases (29.6) (25.2) (23.1)

Net payments under credit facilities (4.9) (14.0) (5.6)

Debt issuance costs — (6.2) —

Receipt of convertible note capped call 76.1 — —

Sale to noncontrolling interests — — 6.4

Dividends paid to noncontrolling interests (16.0) (16.0) (34.0)

Cash provided by (used in) financing activities (260.4) 267.2 (201.9)

Effect of exchange rate changes on cash and cash equivalents (7.6) — —

Less: Cash held for sale (2.3) — —

Increase (decrease) in cash and cash equivalents (22.7) 159.9 (103.7)

Cash and cash equivalents at beginning of year 743.9 584.0 687.7

Cash and cash equivalents at end of year $ 721.2 $ 743.9 $ 584.0

Amounts presented on the Consolidated Statements of Cash Flows may not agree to the corresponding changes in consolidated balance sheet items due to the accounting for purchases and sales of businesses and the effects of foreign currency translation.

The accompanying notes are an integral part of these statements.

45

ATI Inc. and Subsidiaries

Statements of Changes in Consolidated Equity

ATI Stockholders

Other comprehensive income (loss) — — — — 73.9 (18.3) 55.6

Purchase of treasury stock — — — (139.9) — — (139.9)

Dividends paid to noncontrolling interest — — — — — (34.0) (34.0)

Sales of subsidiary shares to noncontrolling interest — — — — — 0.9 0.9

Other comprehensive loss — — — — (15.8) (0.4) (16.2)

Purchase of treasury stock — — — (85.8) — — (85.8)

Dividends paid to noncontrolling interest — — — — — (16.0) (16.0)

Other comprehensive loss — — — — (6.3) (1.6) (7.9)

Convertible note capped call — 76.1 — — — — 76.1

Purchase of treasury stock — — — (260.0) — — (260.0)

Dividends paid to noncontrolling interest — — — — — (16.0) (16.0)

The accompanying notes are an integral part of these statements.

46

Notes to Consolidated Financial Statements

Note 1. Summary of Significant Accounting Policies

Principles of Consolidation and Reporting

The consolidated financial statements include the accounts of ATI Inc. and its subsidiaries. The financial results of majority-owned joint ventures are consolidated into the Company’s operating results and financial position, with the minority ownership interest recognized in the consolidated statement of operations as net income attributable to noncontrolling interests, and as equity attributable to the noncontrolling interests within total stockholders’ equity. The results for the Shanghai STAL Precision Stainless Steel Company Limited (STAL) are reported on a one month lag. Investments in which the Company exercises significant influence, but which it does not control (generally a 20% to 50% ownership interest) are accounted for under the equity method of accounting, whereby ATI’s carrying value of the equity method investment on the consolidated balance sheet is the capital investment and any undistributed profit or loss. The investments are classified in other (noncurrent) assets on the consolidated balance sheet. The profit or loss attributable to ATI from equity method investments is included in the consolidated statements of operations as a component of Other (non-operating) income (expense). See Note 7 for further explanation of the Company’s joint ventures. Intercompany accounts and transactions have been eliminated. Unless the context requires otherwise, “ATI” and the “Company” refer to ATI Inc. and its subsidiaries.

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. Unless otherwise stated, references to years in this Annual Report on Form 10-K relate to fiscal years, rather than calendar years. Fiscal years 2024, 2023 and 2022 ended on December 29, 2024, December 31, 2023 and January 1, 2023, respectively. All fiscal years presented include 52 weeks of operations.

Risks and Uncertainties and Use of Estimates

The preparation of consolidated financial statements in conformity with United States (U.S.) generally accepted accounting principles requires management to make estimates and assumptions that affect reported amounts of assets and liabilities at the date of the financial statements, as well as the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Management believes that the estimates are reasonable.

The Company markets its products to a diverse customer base, principally throughout the U.S. No single customer accounted for more than 10% of sales for any year presented. The core end markets for ATI’s products are customers in the aerospace & defense, specialty energy, electronics, and medical markets.