tndm-20251231

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

_________________________________________________________________

FORM 10-K

_________________________________________________________________

For the fiscal year ended December 31, 2025

For the transition period from to

Commission File Number 001-36189

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Tandem Diabetes Care, Inc.

(Exact name of registrant as specified in its charter)

_________________________________________________________________

San Diego California (Zip Code)

(Address of principal executive offices)

(858) 366-6900

Registrant’s telephone number, including area code

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

Title of Each Class Trading Symbol(s) Name of Each Exchange on Which Registered

Common Stock, par value $0.001 per share TNDM Nasdaq Global Market

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

____________________________________________________None__________________________________________________

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

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

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

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

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

Large accelerated filer x Accelerated filer ☐

Non-accelerated filer ☐ Smaller reporting company ☐

Emerging growth company ☐

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

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

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

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

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

As of June 30, 2025, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the registrant’s common stock held by non-affiliates was approximately $1.3 billion based on the closing price for the common stock of $18.64 on that date. Shares of common stock held by each executive officer, director, and their affiliated stockholders have been excluded from this calculation as such persons may be deemed to be affiliates. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

As of February 16, 2026, there were 68,325,927 shares of the registrant’s common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive Proxy Statement on Schedule 14A for the 2026 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission not later than 120 days after the end of the fiscal year covered by this Form 10-K, are incorporated by reference in Part III, Items 10-14 of this Form 10-K.

TABLE OF CONTENTS

Part I

Item 1 Business 5

Item 1A Risk Factors 17

Item 1B Unresolved Staff Comments 53

Item 1C Cybersecurity 54

Item 2 Properties 55

Item 3 Legal Proceedings 55

Item 4 Mine Safety Disclosures 55

Part II

Item 6 [Reserved] 57

Item 7A Quantitative and Qualitative Disclosure About Market Risk 68

Item 8 Consolidated Financial Statements and Supplementary Data 70

Item 9A Controls and Procedures 103

Item 9B Other Information 106

Part III

Item 10 Directors, Executive Officers and Corporate Governance 107

Item 11 Executive Compensation 107

Item 14 Principal Accountant Fees and Services 107

Part IV

Item 15 Exhibits and Financial Statement Schedules 108

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K for the fiscal year ended December 31, 2025, or this Annual Report, contains “forward-looking statements” within the meaning of the federal securities laws, which statements are subject to considerable risks and uncertainties. These forward-looking statements are intended to qualify for the safe harbor from liability established by the Private Securities Litigation Reform Act of 1995. All statements included or incorporated by reference in this Annual Report, other than statements of historical fact, are forward-looking statements. You can identify forward-looking statements by the use of words such as “may,” “will,” “could,” “anticipate,” “expect,” “intend,” “believe,” “continue” or the negative of such terms, or other comparable terminology. Forward-looking statements also include the assumptions underlying or relating to such statements. In particular, forward-looking statements contained in this Annual Report may relate to, among other things, our future or assumed financial condition, results of operations, liquidity, trends impacting our financial results, the impact of our foreign currency forward hedging contracts, including business forecasts and plans, research and product development plans, manufacturing plans, strategic plans and objectives, capital needs and financing plans, product launches, geographic expansion, distribution plans, production capacity, clinical trials, regulatory approvals, competitive position and the impact of changes in the competitive environment, supply chain, and the business of our contract manufacturers and suppliers, integration of acquisitions and partner technologies, cybersecurity threats, macroeconomic pressures or uncertainties and the application of accounting guidance. We caution you that the foregoing list may not include all of the forward-looking statements made in this Annual Report. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Annual Report on Form 10-K, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

Our forward-looking statements are based on our management’s current assumptions and expectations about future events and trends, which affect or may affect our business, strategy, operations or financial performance. Although we believe that these forward-looking statements are based upon reasonable assumptions, they are subject to numerous known and unknown risks and uncertainties and are made in light of information currently available to us. Our actual financial condition and results could differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth below under the caption “Risk Factors” in Part I, Item 1A and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Part II, Item 7, and elsewhere in this Annual Report, as well as in the other reports we file with the Securities and Exchange Commission, or the SEC. You should read this Annual Report with the understanding that our actual future results may be materially different from and worse than what we expect.

Moreover, we operate in an evolving environment. New risk factors and uncertainties emerge from time to time and it is not possible for our management to predict all risk factors and uncertainties, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements.

Forward-looking statements speak only as of the date they were made, and, except to the extent required by law or the rules of the Nasdaq Stock Market, we undertake no obligation to update or review any forward-looking statement because of new information, future events or other factors.

We qualify all of our forward-looking statements by these cautionary statements.

Risk Factor Summary

Below is a summary of material factors that make an investment in our securities speculative or risky. Importantly, this summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary, as well as other risks that we face, can be found below, under the heading “Risk Factors” in Part I, Item 1A of this Annual Report, and should be carefully considered, together with other information in this Annual Report, before making investment decisions regarding our securities.

Risks Related to Our Business and Industry

•We have incurred significant operating losses since inception and cannot assure you that we will achieve sustained profitability.

•We currently rely on sales of insulin pump products to generate a significant portion of our sales, and any factors that negatively impact sales of these products may adversely affect our business, financial condition and operating results.

•We are implementing a multi-channel managed care strategy in the United States that impacts the pricing model for our pumps and our supplies sold through the pharmacy channel. If our pharmacy channel strategy fails to achieve its intended outcome, our growth, business, results of operations, and financial condition could be materially and adversely impacted.

•Our ability to maintain and grow our sales depends in part on retaining a high percentage of our customer base.

•Failure to secure or retain adequate coverage or reimbursement for our current and future products by third-party payors could adversely affect our business, financial condition and operating results.

•Competing products, therapeutic techniques or other technological developments and breakthroughs for the monitoring, treatment or prevention of diabetes may render our products obsolete or less desirable or reduce the size of our potential market.

•Our sales and marketing efforts depend on independent distributors who are free to market products that compete with our products. If we are unable to maintain or expand our network of independent distributors, our sales may be negatively affected.

•We are dependent on clinical investigators and clinical sites to enroll participants in our current and anticipated clinical trials and human factors studies, and the failure to successfully complete clinical trials and studies could prevent us from obtaining regulatory clearances, certifications, or approvals for or commercializing our products.

•Any concerns regarding the safety or efficacy of our products could limit sales and cause unforeseen negative effects to our business prospects and financial results.

•We depend on a limited number of third-party suppliers for certain components and products, and the loss of any of these suppliers, their inability to provide us with an adequate supply of components or products, or our inability to adequately forecast customer demand, could harm our business.

Risks Related to Our International Operations

•Commercializing our products internationally may result in a variety of risks associated with international operations that could materially adversely affect our business.

•Failure to obtain any required regulatory authorization, clearance or certification in foreign jurisdictions will prevent us from marketing our products in international markets.

Risks Related to Our Indebtedness

•Servicing Convertible Senior Notes due 2029 (the 2029 Notes) will require a significant amount of cash, and we may not have sufficient cash flow from our business to repay the 2029 Notes.

Risks Related to Our Future Financings and Financial Results

•We may need or otherwise determine to raise additional funds in the future and if we are unable to raise additional funds when necessary or desirable, we may not be able to achieve our strategic objectives.

•Our operating results may fluctuate significantly from quarter to quarter.

Risks Related to Macroeconomic Conditions and External Factors

•Uncertainty in current global economic and political conditions could adversely affect our ability to predict product demand and impact our financial results and make it more likely that our actual results could differ materially from expectations.

•Public health threats, epidemics, or pandemics could have a material adverse effect on our operations, the operations of our business partners, and the global economy as a whole.

•Because our business is global, our sales and profits may fluctuate or decline in response to changes in foreign currency exchange rates or other international risks.

Risks Related to Privacy and Security

•We are subject to stringent and evolving United States and foreign laws, regulations, and rules, contractual obligations, policies and other obligations related to data privacy and security. Our actual or perceived failure to comply with such obligations could lead to regulatory investigations or actions; litigation (including class claims) and mass arbitration demands; fines and penalties; disruptions of our business operations; reputational harm; loss of sales or profits; loss of customers; and other adverse business consequences.

•If our information technology systems or those of third parties with whom we work, our data, or our software are or were compromised, we could experience adverse consequences resulting from such compromise, including but not limited to regulatory investigations or actions; litigation; fines and penalties; disruptions of our business operations; harm to our reputation; loss of sales or profits; loss of customers; and other adverse consequences.

Risks Related to Legal and Intellectual Property

•Our ability to comprehensively protect our intellectual property and proprietary technology is uncertain.

•Patent litigation in the medical device industry is common, and we may be subject to litigation that could cause us to incur substantial costs and divert the attention of management from our business.

•We may be subject to damages resulting from claims that we, or our employees, have wrongfully used or disclosed trade secrets or other proprietary information of our competitors.

Risks Related to Our Regulatory Environment

•Our products and operations are subject to extensive governmental regulation, and failure to comply with applicable requirements could cause our business to suffer.

•New products or modifications to our existing products may require new 510(k) clearances, PMAs, CE Marks or other certifications, or may require us to cease marketing or recall the modified products until clearances, certifications or approvals are obtained.

•A recall or suspension of our products, or the discovery of serious safety issues with our products, could have a significant negative impact on us.

Other Risks

•The price of our common stock may continue to fluctuate significantly.

•We depend on the knowledge and skills of our senior management and other key employees, and if we are unable to retain and motivate them or recruit additional qualified personnel, our business may suffer.

•Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

PART I

Item 1. Business

References within this Annual Report to “Tandem,” “we,” “our,” “us,” “management,” or the “Company” refer to Tandem Diabetes Care, Inc., together with its wholly-owned subsidiaries.

Overview

Tandem Diabetes Care is a global leader in insulin delivery and diabetes technology, specializing in the design, development, and commercialization of advanced solutions that reduce the burden of diabetes management. We serve nearly 500,000 people living with diabetes in more than 25 countries worldwide. Our strategy is to offer flexibility and choice in intelligent insulin delivery systems through an accessible portfolio of market-leading pumps, applications and insights. In support of this strategy, our Tandem pump platforms include t:slim X2 and Tandem Mobi (Mobi), both of which feature Control-IQ+ advanced hybrid closed-loop technology.

Diabetes and the Insulin Therapy Management Market

Diabetes is a chronic, life-threatening disease for which there is no known cure. It is typically classified as either type 1 or type 2:

•Type 1 diabetes is characterized by the body’s nearly complete inability to produce insulin. It is frequently diagnosed as an acute event during childhood or adolescence. Individuals with type 1 diabetes require intensive insulin therapy to survive.

•Type 2 diabetes is characterized by the body’s inability to either properly use insulin or produce enough insulin. It’s a progressive condition, and a person in the advanced stages of living with type 2 diabetes often requires intensive insulin therapy. The Center for Disease Control and Prevention estimates Type 2 accounts for 90-95% of diagnosed diabetes in adults in the United States.

We consider our addressable market to be people living with type 1 diabetes and in 2025, we began expanding our addressable market to include people living with type 2 diabetes who require intensive insulin therapy. Throughout this Annual Report, we refer to these individuals as people with insulin-dependent diabetes. In the geographies we serve, we estimate about 5 million people live with type 1 diabetes of whom approximately 2 million reside in the United States. We estimate about 2.5 million people in the United States live with type 2 diabetes and require intensive insulin therapy.

Diabetes can be challenging to manage. Unlike most therapies, insulin requirements can vary greatly and can be affected by many factors, such as type or quantity of food eaten, illness, stress and exercise. Preventing andmanaging fluctuations in blood glucose levels between hypoglycemia, or low blood glucose levels, and hyperglycemia, or high blood glucose levels, is often time consuming and stressful.

There are two primary therapies used by people with insulin-dependent diabetes, Multiple Daily Injection (MDI) and insulin pumps. Insulin pumps are intended to more closely resemble the physiologic function of a healthy pancreas and use rapid-acting insulin to fulfill both mealtime (bolus) and background (basal) requirements. Insulin pump systems are typically considered either durable or disposable. Durable systems are comprised of a programmable device, which is designed to last for multiple years, and which connect to single-use supplies that provide an insulin reservoir and cannula to administer insulin into the body that are expected to be replaced every three to seven days. By comparison, disposable systems combine the programmable device, which includes battery and electronics, with the insulin reservoir and cannula and are entirely disposed of by the user every three days. In both systems, the insulin reservoir is typically filled by the user.

Insulin pumps often feature automated insulin delivery (AID) algorithms, which use continuous glucose monitoring (CGM) sensor information to automatically adjust insulin dosing, and are designed to improve blood glucose control and increase a user’s time in their targeted glycemic range, while reducing the burden of diabetes management. The American Diabetes Association Standards of Care state that diabetes devices should be offered to people with diabetes. It also states that AID systems are preferred over non-automated pumps and MDI, and should be offered for diabetes management to youth and adults with type 1 diabetes. The worldwide insulin pump market remains highly underpenetrated. In the United States, approximately 40% of individuals with Type 1 diabetes, and 5% of individuals with Type 2 diabetes, use insulin pump therapy. Internationally, average insulin pump adoption is estimated to be approximately 20%.

Our Technology: Improving the Lives of People with Insulin-Dependent Diabetes

Our AID Systems

We develop our automated insulin delivery systems and related technology solutions using a consumer-focused approach. We initially rely on the use of behavioral sciences, including extensive research to ascertain what people with insulin-dependent diabetes require and prefer from their diabetes therapy. We then look to modern consumer technology for inspiration and design our hardware and software solutions to try to meet the specific demands of people living with diabetes. This multi-step approach has resulted in a differentiated device portfolio that provide users with the distinct features and functionality they seek and in a manner that makes the features usable and intuitive.

We offer durable insulin pumps that are designed for years of daily use. We sell single-use supplies that are used together with our pumps and are replaced every few days. These supplies include cartridges for storing insulin, and infusion sets that contain a cannula and connect the pump to a user’s body to administer insulin. We launched our flagship t:slim pump platform in August 2012, and its next generation, the t:slim X2, in October 2016. In 2024, we expanded our portfolio with the commercial availability of Mobi with iOS control in the United States. In December 2025, we further expanded the availability of Mobi to Android users in the U.S. Our insulin pumps are fully detachable, offer Bluetooth connectivity and are typically used as part of an AID system.

Key Features Mobi t:slim X2

Control-IQ Technology X X

Remote Software Updates X X

On-body Wear X

Smartphone Control X Mobile Bolus

Insulin Capacity 200 units 300 units

Integrated Color Touchscreen X

Pump Button for Bolus Delivery X X

When used as an AID system, our insulin pumps are integrated with a CGM and powered by our Control-IQ+ technology. Results from four independent pivotal studies using Control-IQ technology have been published in the New England Journal of Medicine since 2019. Control-IQ+ launched in 2025 and is our third and newest AID algorithm, which is available globally and indicated for people as young as ages 2+ (type 1). It is also indicated for people 18+ (type 2) in the United States. This hybrid closed loop algorithm increases a user's time in targeted glycemic range (70-180 mg/dL) by predicting and helping to prevent the frequency and/or duration of hyperglycemic and/or hypoglycemic events. It is the only predictive algorithm featuring AutoBolus, corrective bolusing. Control-IQ+ also offers an easy set-up feature and settings for sleep and exercise activities that adjust the algorithm parameters to better match the different physiological needs during these activities.

Our AID systems offer users the choice of integrating with multiple CGM sensors. In 2025, our pumps integrated with sensors such as the Dexcom G6 and G7, and the Abbott FreeStyle Libre 2 Plus. In December 2025, we launched t:slim X2 integration with Abbott FreeStyle Libre 3 Plus in the U.S. Mobi was available with Dexcom G6 and G7 integration in the U.S., and we plan to expand its integration offerings to include Abbott FreeStyle Libre 3 Plus. Our extensive experience in CGM integration over the past decade represents our commitment to provide customizable solutions to help reduce burden and create new possibilities for people living with diabetes.

Tandem Device Updater

This tool allows Tandem pump users to update their pump software quickly and easily from a personal computer. It is PC and Mac compatible and designed to work with our pumps in a manner similar to software updates on a smartphone. We have used this technology worldwide to offer software updates to our in-warranty customers at no cost.

Tandem Source

Our web-based data management platform provides users, their caregivers and their healthcare providers with a fast, easy and visual way to display diabetes therapy management data from our pumps and integrated CGMs. Tandem Source also provides us with data that we can analyze to reveal patterns, trends, outcomes and associations that can be used to improve our products and in the analysis of clinical outcomes data. Tandem Source is available in the majority of markets we serve globally and was designed to bring together the features of Tandem’s legacy t:connect, t:connect HCP, and t:connect Portal offerings with new comprehensive data reporting in one central, scalable platform. It offers automatic data transfers from pumps using a mobile app to keep online data current and remove the need for manual pump uploads.

Sugarmate

Sugarmate is a mobile app that is designed to help people visualize diabetes therapy data in innovative ways. It allows users to log glucose data and health and nutrition information, and can provide notifications and alerts to users, their family, and their caregivers.

Our Strategy & Future Technologies

Diabetes management can vary greatly from person-to-person, creating multiple market segments based on clinical needs, personal preferences and affordability. Our strategy is to redefine global leadership in insulin delivery solutions through commercial excellence, patient-first reimbursement choices, and a differentiated device portfolio. We strive to offer all people with insulin-dependent diabetes flexibility and choice in their intelligent insulin delivery systems, through our portfolio of market-leading pumps, applications, and insights that improve outcomes and reduce the daily burden of living with diabetes.

In support of this strategy, we continue to drive innovation in our Tandem pump platforms. This includes a novel, extended-wear infusion site option for Mobi that will transform the pump into a tubeless patch device. In addition, our pipeline also includes a next-generation Mobi patch pump that leverages the technology acquired with the Sigi Patch Pump to deliver further miniaturization. Our development efforts also include extended-wear infusion set technology, dual glucose-ketone sensor integration, and algorithm advancement in pursuit of offering fully closed loop technology.

Markets and Distribution Methods

Our technology solutions are now available in more than 25 countries. In the United States and Canada, we have always employed direct sales, customer support, and clinical teams, partnering with independent distributors for order fulfillment. Internationally, we have historically contracted with distributors who have substantial responsibility for sales, customer support, clinical efforts and order fulfillment. We began direct sales, training and customer support activities in 2026, starting with the United Kingdom, Austria, and Switzerland, and intend to continue this transition in additional markets across 2026.

Sales Concentrations and Significant Customers. A small number of independent distributors in the United States and Canada are responsible for order fulfillment. We believe these distributors carry minimal inventory at any given time. In other markets, there may be variability in inventory levels among our distributors, particularly when we begin the transition to our own direct operations or in periods surrounding the launch of new products. For the year ended December 31, 2025, two independent distributors each accounted for more than 10% of our worldwide sales.

Third-Party Reimbursement

In the United States, we are pursuing a multi-channel coverage and reimbursement strategy, enhancing coverage and reimbursement through both the durable medical equipment (DME) and pharmacy channels. We believe this strategy will improve access and optimize the potential for better medical outcomes for people living with diabetes, while reducing the overall economic burden of diabetes care. This also provides our customers with flexibility in how they use their insurance benefits to simplify onboarding and provide them with the most advantageous reimbursement terms. Our increasing use of the pharmacy channel is discussed in this Annual Report under Part II, Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Internationally, insurance reimbursement processes vary by geography. In markets where we have direct operations, we are responsible for all reimbursement, tender application and fulfillment activities. Otherwise, that responsibility lies with our distributors.

Manufacturing and Quality Assurance

Our insulin pumps are currently assembled, tested, and packaged at our facilities in San Diego, California. Our t:slim X2 cartridges are manufactured by an experienced third-party contract manufacturer and packaged at our facilities in San Diego. Our Mobi cartridges have primarily been manufactured at our facilities in San Diego since launch, but we are in the process of transferring those operations to the same contract manufacturer who makes our t:slim X2 cartridges.

Outside suppliers are the source for raw materials, select components and some sub-assemblies used in the production of our insulin pumps and cartridges. We purchase some supplies from a single or limited number of sources because of their proprietary know-how, quality assurance, cost-effectiveness, or constraints due to regulatory requirements. For example, we purchase all of our currently marketed infusion sets from a third-party supplier, Unomedical A/S, a subsidiary of the ConvaTec Group. Unomedical is responsible for all manufacturing, testing, sterilization and packaging of the infusion sets under our brands. Any sole and single source supplier is managed through our supplier management program that is focused on reducing supply chain risk. Certain suppliers are evaluated, approved and monitored periodically by our quality department to ensure conformity with the specifications, policies and procedures applicable to our devices. Members of our quality department also inspect a sample of devices at various steps during the manufacturing cycle to facilitate compliance with our devices’ stringent specifications.

As a medical device manufacturer, our manufacturing facility and the facilities of our sterilization and other critical suppliers are subject to periodic inspection by the FDA, certain corresponding state agencies, and Notified Bodies and foreign regulatory authorities. We have received certification from BSI Group, a Notified Body to the International Standards Organization (ISO), of our quality system. A Notified Body is an entity that has been designated and accredited by the national competent authority of an EU Member State in accordance with applicable EU legislation to perform third-party conformity assessment activities including calibration, testing, certification and inspection of a medical device. Certain processes used in the manufacturing and testing of our devices have been verified and validated as required by the FDA and other regulatory bodies.

We also work closely with our suppliers to ensure continuity of supply while maintaining high quality and reliability. However, due to required medical device manufacturing qualification requirements, we may not be able to quickly establish additional or replacement sources. In the case of sole sourced parts, we manage risk through holding inventory in house and at the supplier to ensure continuity of supply and lower risk of disruption. We purchase many of our components and sub-assemblies from manufacturers with whom we are at least dual sourced and across various geographies.

Intellectual Property

We have made protection of our intellectual property a strategic priority. We rely on a combination of copyright, patent, trademark, trade secret and other intellectual property laws, non-disclosure agreements and other measures to protect our proprietary rights.

As of December 31, 2025, our patent portfolio included numerous issued patents and pending patent applications in the United States and other countries, which in the aggregate, we believe to be important to our business. Patents are generally effective for 20 years from the date the earliest application was filed in the patent family, and in some cases may be extended. Our issued patents as of December 31, 2025 are set to expire over a range of years, from 2026 to 2044, subject to any extensions. We also have various registered United States trademarks, registered European Community trademarks, and other trademark registrations and pending trademark applications in other countries and regions of the world. In addition, we have entered into exclusive and non-exclusive licenses in the ordinary course of business relating to a wide array of technologies or other intellectual property rights or assets.

Our patents and patent applications seek to protect aspects of key features of our pumps, cartridges, algorithms, infusion sets and pump systems. We believe that our patent position provides us with sufficient rights to protect our current and proposed commercial products. However, our patent applications may not result in issued patents, and any patents that have been issued or might be issued may not protect our intellectual property rights. Furthermore, we operate in an industry characterized by extensive patent litigation, and our patents may not be upheld if challenged. Any patents issued to us may be challenged by third parties as being invalid or unenforceable, and patent litigation may result in significant damage awards and injunctions that could prevent the manufacture and sale of affected products or result in significant royalty payments to continue selling the products. Third parties may also independently develop similar or competing technology that avoids our patents. The steps we have taken may not prevent the misappropriation of our intellectual property, particularly in foreign countries where the laws may not protect our proprietary rights as fully as in the United States. We also face risks associated with intellectual property infringement.

We also rely on trade secrets, technical know-how and continuing innovation to develop and maintain our competitive position. We seek to protect our proprietary information and other intellectual property by generally requiring our employees, consultants, contractors, suppliers, outside scientific collaborators and other advisors to execute non-disclosure and assignment of invention agreements at the start of their employment or engagement. Agreements with our employees also forbid them from bringing the proprietary rights of third parties to us. We also generally require confidentiality or material transfer agreements from third parties that receive our confidential data or materials. We cannot guarantee that employees and third parties will abide by the confidentiality or assignment terms of these agreements. Despite measures taken to protect our intellectual property, unauthorized parties might copy aspects of our products or obtain and use information that we regard as proprietary.

Competition

The medical device industry is intensely competitive, subject to rapid change and highly sensitive to the introduction of new products, treatment techniques or technologies, or other market activities of industry participants. We compete in markets worldwide with companies that manufacture insulin delivery devices, primarily Beta Bionics, Insulet, Medtronic, mylife (formerly Ypsomed) and Sequel. There are also a number of other companies developing and marketing their own insulin delivery systems and/or related software applications for launch in the markets where we operate. In addition, we face competition from a number of companies, medical researchers and existing pharmaceutical companies that are pursuing new delivery devices, sensing technologies, procedures, drugs and other therapeutics for the monitoring, treatment and prevention of diabetes.

Government Regulation

The medical devices that we manufacture are subject to regulation by numerous regulatory bodies, including the FDA and comparable international regulatory agencies. These agencies require manufacturers of medical devices to comply with applicable laws and regulations governing the development, testing, manufacturing, labeling, marketing and distribution of medical devices. Devices are generally subject to varying levels of regulatory control, the most comprehensive of which requires that a clinical evaluation program be conducted before a device receives approval for commercial distribution. In addition, healthcare regulatory bodies in the United States and around the world impose a range of requirements related to the payment for medical devices and the procedures in which they are used, including laws intended to prevent fraud, waste, and abuse of healthcare dollars.

Regulation of Medical Devices in the United States

Our products are medical devices subject to extensive and ongoing regulation by the FDA and other federal and state regulatory authorities. The FDA’s regulations govern product design and development, pre-clinical and clinical testing, pre-market clearance, authorization or approval, establishment registration and product listing, product manufacturing, product labeling, product storage, advertising and promotion, product sales, distribution, recalls and field actions, servicing and post-market clinical surveillance. Unless an exemption applies, each new or significantly modified medical device we seek to commercially distribute in the United States will require either a pre-market notification under Section 510(k) of the U.S. Federal Food, Drug and Cosmetic Act (FDCA), also referred to as a 510(k) clearance, or approval from the FDA through the premarket approval (PMA) process. Both the 510(k) clearance and PMA processes can be lengthy and expensive. We have obtained 510(k) clearance on multiple devices in both Class II and Class III, including our Control IQ technology, the t:slim X2 and Tandem Mobi. In addition, we may be required to obtain a new 510(k) clearance or PMA for significant post-market modifications to our products.

There are three types of interoperable FDA Class II devices (integrated continuous glucose monitoring systems (iCGMs), Alternate Controller Enabled (ACE) insulin pumps, and interoperable automated glycemic controllers (iAGC)) in a complete AID system. The classification of these three device types into Class II is intended to help support continued rapid innovation by streamlining the FDA regulatory pathway for integrated CGM and insulin pumps with advanced algorithms. Our pumps are classified as ACE pumps that are compatible with iCGM devices, and our Control-IQ and Control-IQ+ technologies are classified as an iAGC for people living with type 1 diabetes ages 2 and older. In March 2025, our Control-IQ+ technology was cleared for people living with type 2 diabetes ages 18 and older. In connection with the de novo applications for both the ACE pump and the iAGC category, the FDA established certain special controls that we will need to continue to satisfy. If we are not able to satisfy those special controls, we would be required to seek approval for those products under the traditional PMA submission application, which must be supported by valid scientific evidence that typically includes extensive technical, pre-clinical, clinical, manufacturing and labeling data to demonstrate to the FDA’s satisfaction the safety and efficacy of the device.

Clinical trials are typically required to support a PMA application and are sometimes required for 510(k) clearance. We anticipate that most of our future AID offerings will require supporting clinical data, either from clinical trials or potentially from evidence that we are able to collect through real-world use of our products. These trials generally require submission of an application for an Investigational Device Exemption (IDE) to the FDA. The IDE application must be supported by appropriate data, such as animal and laboratory testing results, showing that it is safe to test the device in humans and that the testing protocol is scientifically sound. Generally, clinical trials for a significant risk device may begin once the IDE application is approved by the FDA, and the study protocol and informed consent are approved by appropriate institutional review boards at the clinical trial sites. The FDA’s approval of an IDE allows clinical testing to go forward, but it does not bind the FDA to accept the results of the trial as sufficient to prove the product’s safety and efficacy, even if the trial meets its intended success criteria.

Other Regulatory Requirements. Even after a device receives clearance or approval and is placed in commercial distribution, numerous regulatory requirements apply. These include:

•establishment registration and device listing;

•quality management system regulations (QMSR), which requires manufacturers, including third-party manufacturers, to follow stringent design, testing, production, control, supplier/contractor selection, complaint handling, documentation and other quality assurance procedures during all aspects of the manufacturing process;

•labeling regulations that prohibit the promotion of products for uncleared, unapproved or “off-label” uses, and impose other restrictions on labeling, advertising and promotion;

•the FDA’s Medical Device Reporting (MDR) regulations, which require that manufacturers report to the FDA if their device may have caused or contributed to a death or serious injury or malfunctioned in a way that would likely cause or contribute to a death or serious injury if the malfunction were to recur;

•voluntary and mandatory device recalls to address problems when a device is defective and could be a risk to health; and

•corrections and removals reporting regulations, which require that manufacturers report to the FDA field corrections and product recalls or removals if undertaken to reduce a risk to health posed by the device or to remedy a violation of the FDCA that may present a risk to health.

Also, the FDA may require us to conduct post-market surveillance studies or establish and maintain a system for tracking our products through the chain of distribution to the patient level. We are currently conducting a post-market surveillance study for Control-IQ+ technology for users 2-5 years of age. We may elect to pursue additional post-market surveillance studies in the future.

The FDA and the Food and Drug Branch of the California Department of Health Services enforce regulatory requirements by conducting periodic, unannounced inspections and market surveillance. Inspections may include the manufacturing facilities of our subcontractors. If the FDA believes we or any of our contract manufacturers or regulated suppliers are not in compliance with these requirements, it can shut down our manufacturing operations, require recall of our products, refuse to approve new marketing applications, institute legal proceedings to detain or seize products, enjoin future violations, or assess civil and criminal penalties against us or our officers or other employees. Any such action by the FDA would have a material adverse effect on our business. We may be unable to comply with all applicable FDA regulations.

Licensure. To sell our products through the durable medical equipment (DME) channel in the United States, several states require that DME providers be licensed to sell products to patients in that state. Some of these states require that DME providers maintain an in-state location or retain a licensed pharmacist, and in those states, we sell our products through a third-party distributor. Additionally, to sell our products through the pharmacy channel in the United States, we are required to work with intermediaries who have the appropriate pharmacy licenses. Tandem is also registered throughout the United States to issue payment plans. Although we believe we are in material compliance with applicable state regulations regarding licensure requirements, if we were found to be noncompliant, we could be subject to fines and penalties or lose our licensure in that state, which could prohibit us from selling our current or future products to patients in that state. In addition, we are subject to certain state laws regarding professional licensure. We believe that our certified diabetes educators are in material compliance with such state laws. However, if our educators or we were to be found non-compliant in a given state, we may need to modify our approach to providing education, clinical support and customer service.

Fraud and Abuse Laws. There are numerous U.S. federal and state laws pertaining to healthcare fraud and abuse, including the federal Anti-Kickback Statute and the Physician Self-Referral Law (the Stark Law), the federal civil False Claims Act, the federal criminal Health Care Fraud Statute, as well as various state laws regulating healthcare. Our relationships with healthcare providers and other third parties are subject to scrutiny under these laws. Violations of these laws are punishable by criminal and civil sanctions, including, in some instances, imprisonment and exclusion from participation in federal and state healthcare programs, including the Medicare, Medicaid and Veterans Health Administration programs.

Federal Anti-Kickback Statute. The federal Anti-Kickback Statute prohibits persons from knowingly and willfully soliciting, receiving, offering or providing remuneration, directly or indirectly, in cash or in kind, to induce either the referral of an individual, or the furnishing, recommending, or arranging of a good or service, for which payment may be made under a federal healthcare program such as Medicare and Medicaid.

We provide the initial training to customers necessary for appropriate use of our products either through our own diabetes educators or by contracting with outside diabetes educators who have completed a Tandem pump training course. Outside diabetes educators are reimbursed for their services at fair market value. Although we believe that these arrangements do not violate the Anti-Kickback Statute, regulatory authorities may determine otherwise, especially as enforcement of this law historically has been a high priority for the federal government. Noncompliance with the federal Anti-Kickback Statute could result in our exclusion from Medicare, Medicaid or other governmental programs (which could adversely affect our sales to a material extent), restrictions on our ability to operate in certain jurisdictions, and civil and criminal penalties.

Physician Self-Referral Law.The Stark Law prohibits a physician from referring Medicare or Medicaid patients to an entity providing “designated health services,” including a company that furnishes durable medical equipment, if the physician or their immediate family member has a financial relationship with the company. In addition to statutory exceptions, the Centers for Medicare and Medicaid Services (CMS), has issued numerous regulatory exceptions to the Stark Law. Violation of the Stark Law could result in denial of payment, disgorgement of reimbursements received under a noncompliant arrangement, civil penalties, and exclusion from Medicare, Medicaid or other governmental programs. Although we believe that we have structured our provider arrangements to comply with current Stark Law requirements, these arrangements may not expressly meet the requirements for applicable exception from the law.

Federal False Claims Act. The federal False Claims Act provides, in part, that the federal government may bring a lawsuit against any person whom it believes has knowingly presented, or caused to be presented, a false or fraudulent request for payment from the federal government, or who has made a false statement or used a false record to get a claim approved. In addition, amendments in 1986 to the False Claims Act have made it easier for private parties to bring “qui tam” whistleblower lawsuits under the act. Qui tam actions have increased significantly in recent years, causing greater numbers of healthcare companies to have to defend a false claim action, pay fines and/or be excluded from Medicare, Medicaid or other federal or state healthcare programs as a result of an investigation arising out of such action.

We submit reimbursement claims to federal healthcare programs, and we also may provide some coding and billing information to purchasers of our devices. These activities, if inappropriate, could result in liability under the False Claims Act. Further, claims arising from relationships which violate the Anti-Kickback Statute are considered to be false claims under the False Claims Act. Liability under the False Claims Act may also attach to claims arising from financial relationships which violate the Stark Law. We believe that we currently are in material compliance with the federal government’s laws and regulations concerning the submission of claims and the provision of coding and billing information. However, because we cannot guarantee that the government or qui tam relators will regard any billing errors that may be made as inadvertent, or our provider relationships as compliant, we may have exposure under the False Claims Act.

State Fraud and Abuse Provisions. Many states have also adopted some form of anti-kickback and anti-referral laws and false claims acts. We believe that we are in material conformance to such laws. Nevertheless, a determination of liability under such laws could result in fines and penalties and restrictions on our ability to operate in these jurisdictions.

Health Insurance Portability and Accountability Act of 1996 (HIPAA). HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009 (collectively, HIPAA) mandated the adoption of standards for the exchange of electronic health information to encourage overall administrative simplification and enhance the effectiveness and efficiency of the healthcare industry. Ensuring privacy and security of patient information is one of the key factors driving the legislation. If we are found to violate HIPAA, we could be subject to civil or criminal penalties.

HIPAA and Other U.S. Privacy Laws and Regulations. Numerous federal and state laws, rules and regulations govern the collection, dissemination, use, privacy, security and confidentiality of personal information. HIPAA, in addition to the criminal powers above, extensively regulates the use and disclosure of individually identifiable health information, through the Privacy, Security, and Breach Notification Rules. HIPAA requires covered entities, including health plans and most health care providers, to implement administrative, physical and technical safeguards to protect the privacy and security of covered information (known as “protected health information”) and sets limits and conditions on the uses and disclosures that may be made of such protected health information. HIPAA’s Security Rule and certain provisions of the HIPAA Privacy Rule and Breach Notification Rule apply to business associates of covered entities (i.e., entities that provide services to covered entities that may require access and use of protected health information on behalf of covered entities), and business associates are subject to direct liability for violation of these rules. Covered entities must report breaches of unsecured protected health information to affected individuals without unreasonable delay and notification must also be made to the U.S. Department of Health & Human Services, Office for Civil Rights (OCR) and, in certain situations involving large breaches, to the media. The OCR enforces the HIPAA Rules and performs compliance audits and investigations. In addition to enforcement by OCR, HIPAA authorizes state attorneys general to bring civil actions seeking either injunction or damages in response to HIPAA violations that impact state residents.

On December 1, 2022, OCR issued a bulletin on the requirements under HIPAA for online tracking technologies (e.g., cookies, pixels) to protect the privacy and security of health information. This bulletin outlined OCR’s position on the use of online tracking technology vendors, when certain information received by such vendors constitutes protected health information under HIPAA, and accordingly, when business associate agreements must be executed between covered entities, like us, and such vendors. We are a covered entity under HIPAA and in certain circumstances, we may also be a business associate of another covered entity or of another business associate. There are numerous other laws, regulations and legislative and regulatory initiatives at the federal and state levels addressing privacy and security of personal information. We also remain subject to federal and state privacy-related laws that may be more restrictive or contain different requirements than the privacy regulations issued under HIPAA. These laws vary and could impose additional penalties. Further, certain U.S. states have proposed or enacted comprehensive consumer privacy laws and/or laws governing personal health information, such as the California Consumer Privacy Act, or CCPA. Among other things, these state-specific laws create new data privacy obligations for covered companies and provide new privacy rights to state residents, including the right to opt out of certain disclosures of their information. They may also cause us to incur substantial costs and expenses to ensure ongoing compliance. Various U.S. state laws and regulations may also require us to notify affected individuals and state agencies in the event of a data breach involving individually identifiable information.

In addition to the laws discussed above, we may see more stringent state and federal privacy legislation passed, as the increased cyber-attacks during recent international conflicts have once again put a spotlight on data privacy and security in the U.S. and other jurisdictions. We cannot predict where new legislation might arise, the scope of such legislation, or the potential impact to our business and operations.

Healthcare Fraud.In addition to information security and data privacy obligations, HIPAA also created two new federal crimes: healthcare fraud and false statements relating to healthcare matters. The healthcare fraud statute prohibits knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private payors. A violation of this statute is a felony and may result in fines, imprisonment or exclusion from government sponsored programs. The false statements statute prohibits knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. A violation of this statute is a felony and may result in fines or imprisonment.

Physician Payments Sunshine Act.ThePhysician Payments Sunshine Act requires certain manufacturers, including medical device manufacturers, to submit annual data to CMS pertaining to payments or other transfers of value to covered recipients, including physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), other health care professionals (such as physicians assistants and nurse practitioners), and teaching hospitals, as well as information regarding ownership and investment interests held by physicians and their immediate family members. Manufacturers may be subject to audit for their compliance with this law. Failure to submit the required data in an accurate and timely manner may result in the imposition of civil monetary penalties.

Anti-Bribery and Anti-Corruption Laws. The U.S. Foreign Corrupt Practices Act (FCPA), and similar laws in foreign jurisdictions generally prohibit U.S. corporations and their representatives from offering, promising, authorizing or making improper payments, gifts or transfers to any foreign government official to obtain or retain business. The scope of the FCPA would include interactions with certain healthcare professionals and hospital administrators in many countries.

International Regulation

International sales of medical devices are subject to local government regulations, which vary substantially from country to country. The time required to obtain approval in another country may be longer or shorter than that required for FDA approval, and the requirements may differ. There is a trend towards harmonization of quality system standards among the European Union, United States, Canada and various other industrialized countries.

The regulatory framework governing medical devices is largely harmonized within the European Union (EU), which includes most of the major countries in Europe. Other countries, such as Switzerland, have voluntarily adopted laws and regulations that mirror those of the EU with respect to medical devices. In the EU, medical devices are governed by Regulation (EU) 2017/745 on medical devices (MDR), which entered into application on May 26, 2021, repealing and replacing both Directive 93/42/EEC concerning medical devices (MDD) and Directive 90/385/EEC concerning active implantable medical devices (AIMDD). The MDR and its associated guidance documents and harmonized standards regulating the design, development, preclinical and clinical performance premarket conformity assessment, registration, manufacture, labeling storage, claims, sales and distribution, export and import and post-market surveillance, vigilance, and market surveillance for medical devices. To be placed on the EU market, devices must undergo a conformity assessment and bear the CE mark, indicating that the device conforms to the requirements of the MDR. In particular, medical devices must comply with the General Safety and Performance Requirements (GSPRs), set out in Annex I of the MDR. Compliance with these requirements is a prerequisite to affixing the CE mark to devices, without which they cannot be marketed or sold in the European Economic Area (comprised of the 27 EU Member States, Iceland, Liechtenstein and Norway). To demonstrate compliance with the GSPRs and obtain the right to affix the CE mark, medical devices manufacturers must conduct a conformity assessment procedure, which varies according to the type of medical device and its classification. Apart from low-risk medical devices (Class I with no measuring function and which are not sterile), a conformity assessment procedure requires review by a Notified Body. Depending on the relevant conformity assessment procedure, the Notified Body audits and examines the technical documentation and the quality system for the manufacture, design and final inspection of the medical devices. The Notified Body issues a CE Certificate of Conformity following successful completion of a conformity assessment procedure conducted in relation to the medical device and its manufacturer and their conformity with the GSPRs. This Certificate and completion of the related conformity assessment process entitles the manufacturer to affix the CE mark to its medical devices after having prepared and signed a related EU Declaration of Conformity. The MDR provides transitional provisions which, under strict conditions, permit manufacturers to continue to place medical devices on the market on the basis of CE Certificates of Conformity issued by Notified Bodies in accordance with the MDD or the AIMD until December 31, 2027 or December 31, 2028 depending on the risk classification.

Outside of the EU, regulatory approval needs to be sought on a country-by-country basis for us to market our products. Other countries have adopted medical device regulatory regimes, such as Health Canada’s risk classification system for invasive devices, among others. Each country may have its own processes and requirements for medical device licensing, approval, and regulation, therefore requiring us to seek regulatory approvals on a country-by country basis.

Internationally, a range of anti-bribery and anti-corruption laws, as well as some industry-specific laws and codes of conduct, apply to the medical device industry and interactions with government officials and entities and healthcare professionals. Further, the EU member countries have emphasized a greater focus on healthcare fraud and abuse and have indicated greater attention to the industry by the European Anti-Fraud Office. The Code of Ethical Business Practices became effective on January 1, 2017. Increasingly stringent data protection and privacy rules have had and will continue to have substantial impact on the use of patient data across the healthcare industry. The European Union’s General Data Protection Regulation (EU GDPR) and the United Kingdom’s General Data Protection Regulation (UK GDPR) (collectively, GDPR) applies across the EU and includes, among other things, a requirement for prompt notice of data breaches to data subjects and supervisory authorities in certain circumstances and significant fines for noncompliance. Noncompliance could result in the imposition of fines, penalties, or orders to stop noncompliant activities. Due to the strong consumer protection aspects of GDPR, companies subject to its purview are allocating substantial legal costs to the development of necessary policies and procedures and overall compliance efforts. Data transfer risk remains a potential issue that requires regular monitoring. Certain governments around the world are also adopting laws and regulations pertaining to mandatory corporate sustainability reporting.

Environment, Social and Governance

Our Board of Directors and management team believe that environmental stewardship, social responsibility, and solid corporate governance are important to our business strategy and long-term value creation for our shareholders, employees, customers, and communities. The Audit Committee of our Board oversees ESG matters across our business operations in accordance with its charter. Our management team is responsible for developing and driving strategic ESG initiatives and programs across our business and providing regular updates on progress to the Audit Committee.

Additional information about our Environmental, Social and Governance practices as well as our Sustainable Business Report can be found on our website within the “Investor Center” section. The information contained on or accessed through our website does not constitute part of this Annual Report, and references to our website address in this Annual Report are inactive textual references only.

Human Capital

We are committed to creating and maintaining a safe, diverse, and inclusive community for all employees while we serve our customers and fulfill our mission to improve the lives of people with diabetes. As of December 31, 2025, we had approximately 2,500 regular full-time employees, who primarily work in the United States, Canada, or Europe. The term “employees” in this Annual Report means our regular full-time employees. Our headquarters are in San Diego, California, where our primary research and development and administrative functions are located, and where we also operate a manufacturing facility and a warehousing facility. None of our employees are represented by a collective bargaining agreement, and we have never experienced any work stoppage. We believe we have good relations with our employees.

Culture

Fostering and maintaining a strong, healthy culture is a key strategic focus. Our core values statement was created by our employees in a bottom-up, cross-functional process that we revisit and refresh on a periodic basis. Our Words We Live By describe our core values and reflect who we are and the way our employees interact with one another, our customers, partners and stockholders.

We focus on cultivating and encouraging an inclusive and equitable culture where diversity of thought is represented and can thrive throughout our organization. We believe that bringing together different perspectives and experiences is fundamental to innovation and continuing to raise the bar in the field of diabetes technology. Moreover, we are focused on cultivating and supporting our internal culture through diversity of thought, support and advocacy within the diabetes community and continuing to build and maintain a diverse and inclusive workforce.

Organizational Development

Attracting, developing and retaining employees is critical to our longer-term success. We have established a comprehensive training program to develop employees throughout the organization. Emerging Leaders and Leading in Tandem are examples of internal programs intended for high performing individual contributors, and newly hired and promoted supervisors and managers, respectively. More than 94% of employees participating in these programs remained employed at Tandem as of December 31, 2025 and approximately 14% had been promoted or had a significant change in scope of responsibility. In 2025, more than 200 employees participated in our leadership development programs.

Competitive Total Rewards

Our compensation program is designed to align employee compensation with our performance and to provide the proper incentives to attract, retain, and motivate employees to achieve superior results. The structure of our compensation program balances incentive earnings for both short-term and long-term performance.

•We provide employee wages that are competitive and consistent with employee positions, skill levels, experience, knowledge, and geographic location.

•We engage internationally recognized outside compensation and benefits consulting firms to independently evaluate the effectiveness of our executive compensation and benefit programs and to provide benchmarking.

•We align our executives’ long-term equity compensation with our stockholders’ interests.

•Annual increases and incentive compensation are based on Company performance as well as each individual’s contribution to the Company’s achieved results and are documented through our talent management procedures as part of our annual review process.

To foster a stronger sense of ownership and align the interests of partners with stockholders, equity awards are provided to a portion of our employees in line with benchmark practices under our broad-based stock incentive programs. Also, our full-time U.S. employees are able to participate in our employee stock purchase program. Furthermore, we offer comprehensive, locally relevant and innovative benefits to all eligible employees, including health insurance, paid time off, paid and unpaid leaves, defined-contribution retirement plans, health savings accounts, flexible spending accounts, life and disability coverage, voluntary accident, critical illness, legal and identity theft coverage, employee discount programs, and an employee loaner pump program.

Employee Health and Safety

The health and safety of our employees is our highest priority, and this is consistent with our operating philosophy. We have integrated our employee health and safety efforts with our human resources functions to create a corporate culture with a shared commitment to the well-being of our professionals. Our employee assistance and wellness programs offer a range of benefits and services. For example, as a benefit to our employees and their eligible dependents, we provide access to personal and job-related counseling and assistance resources for addressing concerns such as emotional well-being, family and relationships, legal and financial matters, healthy lifestyles, mental health, substance abuse, and work and life transitions.

We have comprehensive safety training programs that teach our employees how to do their jobs safely and in compliance with laws and regulations. We operate in modern, efficient, and safe facilities, and have had minimal accident and injury rates company-wide. Despite this success, our goal remains the same: zero accidents.

Additional Information

Our website address is www.tandemdiabetes.com. Copies of our filings with the SEC, including our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are available free of charge on our website within the “Investor Center” section as soon as reasonably practicable after having been electronically filed with or furnished to the SEC. The information contained on or accessed through our website does not constitute part of this Annual Report, and references to our website address in this Annual Report are inactive textual references only.

Item 1A. Risk Factors.

An investment in our common stock, or in securities convertible into or exchangeable for our common stock, involves a high degree of risk. You should carefully consider the risks described below, together with all of the other information included in this Annual Report, as well as in our other filings with the SEC, in evaluating our business. If any of the following risks actually occur, our business, financial condition, operating results and future prospects could be materially and adversely affected. In that case, the trading price of our common stock may decline and you might lose all or part of your investment. The risks described below are not the only ones we face. Additional risks that we currently do not know about or that we currently believe to be immaterial may also impair our business, financial condition, operating results, liquidity, and future prospects. Certain statements below are forward-looking statements. For additional information, see “Cautionary Note Regarding Forward-Looking Statements” at the beginning of this Annual Report and Part II, Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations of this Annual Report.

Risks Related to Our Business and Our Industry

We have incurred significant operating losses since inception and cannot assure you that we will achieve sustained profitability.

Since our inception in January 2006, we have incurred a significant net loss. As of December 31, 2025, we had an accumulated deficit of $1.3 billion. To date, we have funded our operations primarily through cash collected from product sales, private and public offerings of our equity securities, and debt financings. We have devoted substantially all of our resources to the design, development and commercialization of our products, the scaling of our manufacturing and business operations, and the research and development of our current products and products under development.

Since the first quarter of 2013, we have been able to manufacture and sell our insulin pump products at a cost and in volumes sufficient to allow us to achieve a positive overall gross margin. Although we have achieved a positive overall gross margin during the years ended December 31, 2025, 2024 and 2023, we had net losses from operations in those years, and we may continue to incur net losses from operations in the future.

To implement our business strategy and achieve consistent profitability, we need to, among other things, increase sales of our products through various sales channels and the gross profit associated with those sales, maintain an appropriate customer service, training and support infrastructure, fund ongoing research and development (R&D) activities, create additional efficiencies in our manufacturing processes while adding to our capacity, and obtain regulatory clearance, certification or approval to commercialize our products currently under development both in the United States and in the international countries in which our insulin pumps are available. We expect our expenses will continue to increase as we pursue these objectives and make investments in our business. Additional increases in our expenses without commensurate increases in sales could significantly increase our operating losses.

The extent of our future operating losses and the timing of our profitability are highly uncertain in light of a number of factors, including the timing of the launch of new products and product features by us and our competitors, market acceptance of our products and competing products by people with insulin-dependent diabetes, their caregivers and healthcare providers, the timing of regulatory clearance, certification, or approval of our products and the products of our competitors, the actual efficiencies gained in our manufacturing processes, and general economic conditions. Any additional operating losses will have an adverse effect on our stockholders’ equity, and we cannot assure you that we will be able to achieve and sustain profitability.

We currently rely on sales of insulin pump products to generate a significant portion of our sales, and any factors that negatively impact sales of these products may adversely affect our business, financial condition and operating results.

We generate nearly all of our sales from the sale of our insulin pumps and the related insulin cartridges and infusion sets. Sales of these products may be negatively impacted by many factors, including:

•market acceptance of the insulin pumps and related products manufactured and sold by our key competitors, including Beta Bionics, Insulet, Medtronic, mylife (formerly Ypsomed) and Sequel;

•the potential that breakthroughs for the monitoring, treatment or prevention of diabetes may render our insulin pumps obsolete or less desirable or reduce the size of our potential market;

•adverse regulatory or legal actions relating to our products, or similar products or technologies of our competitors;

•failure of our Tandem Device Updater to accurately and timely provide customers with remote access to new product features and functionality as anticipated, or our failure to obtain regulatory clearance, certification, or approval for any such updates;

•changes in reimbursement rates or policies relating to insulin pumps or similar products or technologies by third-party payors;

•competitive pricing and attrition rates of consumers who cease using our products;

•our inability to enter into contracts with third-party payors on a timely basis and on acceptable terms;

•our inability to expand our sales channels, including the pharmacy channel in the United States;

•problems arising from the expansion of our manufacturing capabilities and commercial operations, or destruction, loss, or temporary shutdown of our manufacturing facilities;

•concerns regarding the perceived safety, reliability or cybersecurity of any of our products, or any component thereof, particularly in connection with the launch of additional mobile app features and functionality and other software products; and

•claims that any of our products, or any component thereof, infringes on patent rights or other intellectual property rights of third parties.

In addition, sales of any of our current or future insulin pump products with CGM integration are subject to the continuation of our applicable agreements with Dexcom, Abbott, or other third parties which, under some circumstances, may be subject to termination, with or without cause, on relatively short notice. Sales of our current or future products may also be negatively impacted in the event of any regulatory or legal actions relating to CGM products that are compatible with our pumps, or in the event of any disruption to the availability of the applicable CGM-related supplies, such as sensors or transmitters, in a given market in which our products are sold. Sales of our products may also be adversely impacted if the CGM products that are compatible with our pumps are not viewed as superior to competing CGM products in markets where our products are sold, or if the price of these products is not competitive with similar products available in the market.

Because we currently rely on sales of our insulin pumps, and related products to generate a significant majority of our sales, any factors that negatively impact sales of these products (or negatively impact the products or components integrated with these products) could adversely affect our business, financial condition and operating results. Furthermore, any disruption in our supply chain could negatively impact our ability to manufacture or otherwise supply sufficient product quantities to meet current customer demand, or any unexpected increase in demand, which could also have the effect of magnifying the negative impact of any of the factors described above.

We are implementing a multi-channel managed care strategy in the United States that impacts the pricing model for our pumps and our supplies sold through the pharmacy channel. If our pharmacy channel strategy fails to achieve its intended outcome, our growth, business, results of operations, and financial condition could be materially and adversely impacted.

We are implementing a multi-channel managed care strategy in the United States, which provides the opportunity for reimbursement through a pharmacy benefit as an alternative to a medical benefit. Historically, our insulin pump products have primarily been considered durable medical equipment (DME) with an expected lifespan of at least four years. Under the DME reimbursement model, our pumps are generally reimbursed upfront. In addition to our insulin pumps, we sell single-use products that are used with our pumps and are replaced every few days, including cartridges for storing and delivering insulin, and infusion sets that connect the insulin pump to a user’s body. Like some of our competitors, we announced that we plan to implement a pharmacy benefit model as an alternative to the DME reimbursement model which will eliminate the upfront pump reimbursement. Under this new model, we may initially experience a decrease in sales and gross profit when pumps are shipped, and while we expect this decrease to be offset by an increase in supply sales and gross profit, there is no assurance that any decrease would be offset by these or other factors. As a result, our financial results may fluctuate or decline compared to prior periods. The success of this shift will depend on, among other things, alignment of and effective execution by our sales organization, timely release of features in our product roadmaps as well as their market acceptance, effective pricing of our offerings, and managing expected commitments to purchase our pumps and supplies. Growth in consumption of our pumps and supplies may in the future be harmed if we do not manage these factors effectively. Our expectation is that a lower upfront cost for pump therapy will accelerate market adoption of our pumps and increase the volume and sales of our supplies over time, which will increase our overall sales per customer. However, there can be no assurance that this strategy will prove successful or that once a customer is obtained, they will continue to purchase supplies in a quantity sufficient to make the strategy successful. As a result, this shift in strategy may materially and adversely impact our growth, business, results of operations and financial condition.

Our ability to maintain and grow our sales depends in part on retaining a high percentage of our customer base.

A key to maintaining and growing our sales is the retention of a high percentage of our customers due to the potentially significant sales generated from ongoing purchases of single-use infusion sets, insulin cartridges and other supplies. In addition, our pumps are designed and tested to remain effective for at least four years and a customer may consider purchasing another pump from us when the time comes to replace it. We have developed retention programs aimed at our customers, their caregivers and healthcare providers, which include training specific to our products, ongoing support by our sales and clinical employees, and technical support and customer service. Demand for our products from our existing customers could decline or could fail to increase as anticipated or projected as a result of a number of factors, including the introduction of competing products, breakthroughs for the monitoring, treatment or prevention of diabetes, changes in reimbursement rates or policies, manufacturing problems, perceived safety or reliability issues with our products or components or the products of our competitors, the failure to secure regulatory clearance, certification, or approvals for products or product features in a timely manner or at all, product development or commercialization delays, the impacts and disruption from health epidemics or pandemics, international conflicts, or for other reasons.

The failure to retain a high percentage of our customers and increase sales to these customers consistent with our forecasts would have a material adverse effect on our business, financial condition and operating results.

Failure to secure or retain adequate coverage or reimbursement for our current and future products by third-party payors could adversely affect our business, financial condition and operating results.

A substantial portion of the purchase price of an insulin pump and supplies is typically paid for by third-party payors, including private insurance companies, preferred provider organizations and other managed care providers. Future sales of our current and future products will be limited unless our customers can rely on third-party payors to pay for all or part of the associated purchase cost. Access to adequate coverage and reimbursement for our current and future products by third-party payors is essential to the acceptance of our products by customers. On December 2, 2025, the Centers for Medicare and Medicaid Services (CMS), which administers the U.S. Medicare program, finalized a proposed competitive bidding process for some medical equipment, including continuous glucose monitors and insulin pumps that could affect reimbursement rates for our products. In addition, CMS finalized a proposed change in payment for these devices to a monthly rental basis which could impact when our pumps are shipped and corresponding sales are recognized.

As guidelines in setting their coverage and reimbursement policies, many third-party payors in the United States use coverage decisions and payment amounts determined by CMS. Medicare periodically reviews its reimbursement practices for diabetes-related products, and there is uncertainty as to the future Medicare coverage structure and reimbursement rate for our products. It is also possible that CMS may continue to review and modify the current coverage and reimbursement of diabetes-related products in connection with anticipated changes to the regulatory approval process for insulin pumps and related products, software applications and services. In addition, third-party payors that do not follow the CMS guidelines may adopt different coverage and reimbursement policies for our current and future products. Further, it is possible that some third-party payors will not offer any coverage for our current or future products. For instance, it is possible that third-party payors may adopt policies in the future that designate one or more of our competitors as their preferred, in-network durable medical equipment provider of insulin pumps and that such policies would discourage or prohibit the payors’ members from purchasing our products, which would adversely impact our ability to sell our products.

We are pursuing a multi-channel managed care strategy and have begun offering pumps and supplies through the pharmacy channel. However, the commercial opportunity in the pharmacy channel will be limited unless a substantial portion of the sales price for any products offered through the pharmacy channel is covered by third-party payors, including private insurance companies, health maintenance organizations, preferred provider organizations, federal and state government healthcare agencies, intermediaries, Medicare, Medicaid and other managed care providers. Medicare Part D plan sponsors may provide coverage for certain products under the Medicare Part D prescription drug program, which requires negotiating with third-party payors to provide these products through the pharmacy channel in the United States. If our efforts to enter into and maintain additional contracts with intermediaries and third-party payors for products we offer or seek to offer through the pharmacy channel take longer than anticipated or are not successful, our ability to successfully offer these products or any future products through the pharmacy channel will be limited.

We believe that there will continue to be proposals by legislators at both the federal and state levels, regulators and third-party payors to reduce costs while expanding individual healthcare benefits. The current administration is pursuing policies to reduce regulations and expenditures across government including at the U.S. Department of Health and Human Services (HHS), the FDA, CMS and related agencies. It is possible that certain of these changes could impose additional limitations on the rates we will be able to charge for our current and future products or the amounts of reimbursement available for our current and future products from governmental agencies or third-party payors. Current and future healthcare reform legislation and policies could have a material adverse effect on our business and financial condition.

We currently have contracts establishing reimbursement for our insulin pump products with a number of national and regional third-party payors in the United States. While we may enter into additional contracts both in the United States and in the international countries in which our insulin pumps and supplies are available through third-party payors, and add coverage for future products under our current agreements, we cannot guarantee that we will succeed in doing so or that the reimbursement contracts that we are able to negotiate will enable us to sell our products on a profitable basis or in certain channels, including the pharmacy channel. In particular, we have limited experience securing reimbursement in international markets. Government involvement in funding healthcare may limit access to or reimbursement for our products. In addition, existing contracts with third-party payors generally include numerous quality and compliance related requirements, including audit rights, and can be modified or terminated by the third-party payor without cause and with little or no notice to us. Our compliance with the administrative procedures or requirements may result in increased costs for us and delays in processing approvals by those third-party payors for customers to obtain coverage for our products, and any payor audits of our compliance obligations may result in requests for refunds or other costs. Failure to secure or retain adequate coverage or reimbursement for our current and future products by third-party payors, or delays in processing approvals by those payors, could result in the loss of sales, which could have a material adverse effect on our business, financial condition and operating results.

Further, the healthcare industry continues to be increasingly focused on cost containment as government and private insurers seek to control healthcare costs by imposing lower payment rates and negotiating reduced contract rates with third-party payors. If third-party payors deny coverage or reduce their current levels of payment, or if our production costs increase faster than increases in reimbursement levels, we may be unable to sell our products on a profitable basis.

We operate in a very competitive industry and if we fail to compete successfully against our existing or future competitors, or if the competitive environment harms our business partners, our financial condition and operating results may be negatively affected.

The medical device industry is intensely competitive, subject to rapid change and highly sensitive to the introduction of new products, treatment techniques or technologies, as well as other activities of industry participants. To continue to compete effectively, we must continue to create, invest in or acquire advanced technology, incorporate this technology into our proprietary products, obtain regulatory clearance, certification, or approvals in a timely manner, and manufacture and successfully market our products. Given these factors, we cannot guarantee that we will be able to compete effectively or continue our level of success.

Our primary competitors are major medical device companies, primarily Beta Bionics, Insulet, Medtronic, mylife (formerly Ypsomed) and Sequel. There are also a number of other companies developing and marketing their own insulin delivery systems and/or related software applications, including insulin pumps and Bluetooth-enabled insulin pens to support MDI therapy. Some of our primary competitors enjoy several competitive advantages over us, including:

•greater financial and human resources for sales and marketing, product development, customer service and clinical resources;

•greater ability to respond to competitive pressures, regulatory uncertainty, or challenges within the financial markets;

•established relationships with healthcare providers, third-party payors and regulatory agencies;

•established reputation and name recognition among healthcare providers and other key opinion leaders in the medical industry generally and the diabetes industry in particular;

•larger and more established distribution networks;

•greater ability to cross-sell products or provide incentives to healthcare providers to use their products; and

•more experience in conducting R&D, manufacturing, clinical trials, and obtaining regulatory approval or clearance.

In addition, the competitive environment in which we operate has resulted and may continue to result in competitive pressures on our manufacturers, suppliers, distributors, collaboration partners and other business constituents. For example, we have entered into development agreements with Dexcom, which provide us with non-exclusive licenses to integrate various generations of Dexcom CGM technology with our insulin pump products. We have also entered into agreements with Abbott to develop and commercialize integrated diabetes solutions using Abbott’s glucose sensors. There can be no assurance that our collaborations with Dexcom and Abbott will be successful or that we will not experience delays, business disputes, or other unanticipated challenges. Competitive pressures within our industry could negatively impact the financial condition of our business partners and impact their ability to fulfill contractual obligations to us, which could negatively impact our product sales, result in delays in obtaining regulatory clearances, certifications, or approvals for new products, harm our reputation, and result in harm to our financial condition and operating results.

For these and other reasons, we may not be able to compete successfully against our current or potential future competitors, which could have a material adverse impact on our financial condition and operating results.

Competing products, therapeutic techniques or other technological developments and breakthroughs for the monitoring, treatment or prevention of diabetes may render our products obsolete or less desirable or reduce the size of our potential market.

Our ability to grow our business and achieve our strategic objectives will depend, among other things, on our ability to develop and commercialize products for the treatment of diabetes that offer distinct features and functionality, are easy-to-use, provide superior treatment outcomes, receive adequate coverage and reimbursement from third-party payors, and are otherwise more appealing than available alternatives. Our primary competitors, as well as a number of other companies and medical researchers are pursuing new delivery devices, delivery technologies, therapeutic techniques, sensing technologies, treatment techniques, procedures, drugs and other therapies for the monitoring, treatment and prevention of diabetes. Any breakthroughs in diabetes monitoring, treatment or prevention could reduce the potential market for our products or render our products obsolete altogether, which would significantly reduce our sales or cause our sales to grow at a slower rate than we currently expect. In addition, even the perception that new products may be introduced, or that technological or treatment advancements could occur and could result in delayed purchases or a decline in market share. For example, since 2023, ongoing adoption of the GLP-1 class of drugs in diabetes and news surrounding the expansion of use of GLP-1 drugs in obesity has likely had a negative impact on the insulin therapy market.

Because the insulin-dependent diabetes market is large and growing, we anticipate companies will continue to dedicate significant resources to developing competing products and technologies. The introduction by competitors of products that are or claim to be superior to our products may create market confusion that may make it difficult to differentiate the benefits of our products over competing products. In addition, some of our competitors employ aggressive pricing strategies, including the use of discounts, rebates, low-cost product upgrades or other financial incentives that could adversely affect sales of our products. If a competitor develops a product that competes with or is perceived to be superior to our products, or if competitors continue to use strategies that place downward pressure on pricing within our industry, our sales may decline, our operating margins could be reduced and we may fail to meet our financial projections, which would materially and adversely affect our business, financial condition and operating results.

Moreover, we have designed our hardware products to resemble modern consumer electronic devices to address certain wearability and functionality concerns consumers have raised with respect to traditional pumps. Similarly, we continue to incorporate new features and functions that are common to other consumer-oriented applications. These consumer industries are themselves highly competitive, and characterized by continuous new product introductions, rapid developments in technology, and subjective and changing consumer preferences. If, in the future, consumers cease to view our products as contemporary or convenient as compared to then-existing consumer technology, our products may become less desirable.

We may face unexpected challenges in marketing and selling our products, and training new customers on the use of our products, which could harm our ability to achieve our sales forecasts.

We have limited experience marketing and selling our newer products as well as training new customers on their use, particularly in international markets. In addition, the vast majority of our existing customers are individuals with type 1 diabetes, and we have limited experience marketing and selling our products to customers with type 2 diabetes.

Our financial condition and operating results are and will continue to be highly dependent on our ability to adequately promote, market and sell our insulin pump and related products, and the ability of our diabetes educators to train new customers on the use of our products. If our sales and marketing representatives or diabetes educators are restricted in their ability to interact with healthcare professionals and customers, our sales could decrease or may not increase at levels that are in line with our forecasts.

Our sales and marketing efforts largely depend on independent distributors who are free to market products that compete with our products. If we are unable to maintain or expand our network of independent distributors, our sales may be negatively affected.

Although we are implementing a multi-channel managed care strategy that includes offering our products through the pharmacy channel, we believe a majority of our sales will continue to be to independent distributors for at least the near term, and it is possible that the percentage of our sales to independent distributors could increase. For example, our dependence upon independent distributors could increase if third-party payors decide to contract with independent distributors directly in lieu of contracting with us to supply our products to their members directly. Our dependence upon independent distributors could also increase if customers prefer to purchase all of their diabetes supplies through a single source, instead of purchasing pump-related products through us and other diabetes supplies through other suppliers. If we are unable to maintain or expand our network of independent distributors, our sales may be negatively affected.

None of our independent distributors in the United States have been required to sell our products exclusively and each of them may freely sell the products of our competitors. As a result, our independent distributors may not devote a sufficient level of resources and the support required to generate awareness of our products and grow or maintain product sales at the levels we expect, which may negatively affect our sales.

If any of our key independent distributors were to cease to distribute our products or reduce their promotion of our products as compared to the products of our competitors, our sales could be adversely affected. In that case, we may need to seek alternative independent distributors or increase our reliance on our other independent distributors, our direct sales representatives or the pharmacy channel, which may not prevent our sales from being adversely affected. Additionally, to the extent we enter into additional arrangements with independent distributors to perform sales, marketing or distribution services, the terms of the arrangements could result in our product margins being lower than if we directly marketed and sold our products.

If the third parties on which we increasingly rely to assist us with our current and anticipated pre-clinical development or clinical trials do not perform as expected, we may not be able to obtain regulatory clearance, certification, or approval or commercialize our products.

As our clinical infrastructure expands, we expect to increasingly rely on third parties, such as contract research organizations, medical institutions, clinical investigators and contract laboratories to conduct some of our current and anticipated pre-clinical investigations and clinical trials. If we are not able to reach mutually acceptable agreements with these third parties on a timely basis, these third parties do not successfully carry out their commitments or regulatory obligations or meet expected deadlines, or the quality or accuracy of the data they obtain is compromised due to the failure to adhere to agreed-upon clinical protocols or regulatory requirements or for other reasons, our pre-clinical development activities or clinical trials may be extended, delayed, suspended or terminated, and we may not be able to obtain regulatory clearance, certification, or approval for, or successfully commercialize, our products on a timely basis, if at all, and our business, operating results and prospects may be adversely affected.

We are dependent on clinical investigators and clinical sites to enroll participants in our current and anticipated clinical trials and human factors studies, and the failure to successfully complete those trials and studies could prevent us from obtaining regulatory clearances, certifications, or approvals for or commercializing our products.

As part of our product development efforts, we expect to increasingly rely on clinical investigators and clinical sites to enroll participants in our clinical trials or users in our human factors testing and other third parties to manage such trials and testing and to perform related data collection and analysis. However, we may not be able to control the amount and timing of resources that clinical sites may devote to our clinical trials or other studies. If these clinical investigators and clinical sites fail to enroll a sufficient number of patients, fail to ensure compliance by patients with clinical protocols, or fail to comply with regulatory requirements, we may be unable to successfully complete our clinical trials or other studies, which could prevent us from obtaining regulatory clearances, certifications, or approvals for our products and commercializing our products, which would have an adverse impact on our business.

If important assumptions about the potential market for our products are inaccurate, or if we have failed to understand what people with insulin-dependent diabetes are seeking in an insulin pump, our business and operating results may be adversely affected.

Our business strategy was developed based on a number of important assumptions about the diabetes industry in general, and the insulin-dependent diabetes market in particular, any one or more of which may prove to be inaccurate or may change over time. For example, we believe that the benefits of insulin pump therapy as compared to other common insulin treatment alternatives will continue to drive growth in the market for insulin pump therapy. In addition, World Health Organization data indicates that the incidence of diabetes in the United States and worldwide is increasing. Further, diabetes management can vary greatly from person to person, creating multiple market segments based on clinical needs and personal preferences. However, each of these assumptions may prove to be inaccurate and limited sources exist to compare treatment alternatives and obtain reliable market data. The actual incidence of diabetes, and the actual demand for our products or competing products, could differ materially from our projections. In addition, until 2025, our strategy has been to focus exclusively on the type 1 diabetes market, and there is no guarantee that we will have commercial success in our efforts to address patients with type 2 diabetes who require intensive insulin therapy.

Another key element of our business strategy is using market research to understand what people with diabetes are seeking to improve in their diabetes therapy management. This strategy underlies our entire product design, marketing and customer support approach and is the basis on which we developed our current products and are pursuing the development of new products. However, our market research is based on interviews, focus groups and online surveys involving people with insulin-dependent diabetes, their caregivers and healthcare providers, which represent only a small percentage of the overall insulin-dependent diabetes market. As a result, the responses we receive may not be reflective of the broader market and may not provide us with accurate insight into the desires of people with insulin-dependent diabetes. In addition, understanding the meaning and significance of such market research responses necessarily requires that analysis be conducted and conclusions be drawn. We may not be able perform an analysis that yields meaningful results, or the conclusions we draw from the analysis could be misleading or incorrect. Moreover, even if our market research has allowed us to better understand the features and functionality consumers are seeking in an insulin pump to improve management of their diabetes therapy, there can be no assurance that consumers will actually purchase our products or that our competitors will not develop products with similar features.

Any concerns regarding the safety and efficacy of our products could limit sales and cause unforeseen negative effects on our business prospects and financial results.

Studies to evaluate the safety or effectiveness of our latest products in a controlled setting are only available over the past few years. As a result, people with insulin-dependent diabetes and healthcare providers may not be familiar with our studies and may be slower to adopt or recommend our products. Further, even with data from controlled studies third-party payors may not be willing to provide coverage or reimbursement for our products. We remain subject to regulatory and product liability risks, and these and other factors could slow the adoption of our products and result in our sales being lower than anticipated. In addition, future studies or clinical experience may indicate that treatment with our products is not superior to treatment with competing products. Such results could slow the adoption of our products and significantly reduce our sales, which could prevent us from achieving our forecasted sales targets or achieving or sustaining profitability.

If the results of clinical studies or other experience, such as our monitoring or investigation of customer complaints, indicate that our products may cause or create an unacceptable risk of unexpected or serious complications or other unforeseen negative effects, we could be required to inform our customers of these risks or complications or, in more serious circumstances, we could be subject to mandatory product recalls, suspension or withdrawal of clearance, certification, or approval from regulatory authorities or Notified Bodies, product recalls or seizure, operating restrictions, interruption of production, fines, civil penalties and criminal prosecution which could result in significant legal liability, harm to our reputation, and a decline in our product sales.

Any actual or alleged illness or injury associated with any of our products or product recalls, software recalls or medical device corrections may negatively impact our financial results and business prospects depending on a number of factors, including the scope and seriousness of the problem, degree of publicity, reaction of our customers and healthcare professionals, competitive response, and consumer perceptions generally. We have initiated voluntary recalls and corrections in the past.

Even if an allegation or product liability claim lacks merit, cannot be substantiated, is unsuccessful or is not fully pursued, the negative publicity surrounding any assertion that our products have caused or carry a risk of causing illness, injury or death could adversely affect our reputation with customers, healthcare professionals, third-party payors, and existing and potential collaborators, and could adversely affect our operating results and cause a decline in our stock price. Furthermore, general concerns regarding the perceived safety or reliability of any of our products, or any component thereof, may have a similar adverse effect on us.

Our ability to achieve profitability will depend, in part, on our ability to reduce the per-unit cost of our products while also increasing production volume.

We believe our ability to reduce the per-unit cost of our insulin pumps and related products will have a significant impact on our ability to achieve profitability. Our cost of sales includes raw materials and component parts, labor costs, product training expenses, freight, reserves for expected warranty costs, royalties, scrap and charges for excess and obsolete inventories. It also includes manufacturing overhead costs, including expenses relating to quality assurance, manufacturing engineering, material procurement and inventory control, facilities, equipment, information technology and operations supervision and management. Our warranty reserve requires a significant amount of judgment and is primarily estimated based on historical experience. Recently released versions of our pump may not incur warranty costs in a manner similar to previously released pumps and the launch of our mobile app also may result in unanticipated changes in historical trends.

If we are unable to increase our production volumes while sustaining or reducing our overall cost of sales, including through arrangements such as volume purchase discounts, negotiation of pricing and cost reductions with our suppliers, more efficient training programs for customers, improved warranty performance or fluctuations in warranty estimates, it will be difficult to reduce our per-unit costs and our ability to achieve profitability will be constrained.

In addition, the per-unit cost of our products is significantly impacted by our overall production volumes, and any factors that prevent our products from achieving market acceptance, cause our production volumes to decline, alter our product mix, result in our sales growing at a slower rate than we expect, or result in the closure of our manufacturing facilities, would significantly impact our expected per-unit costs, which would adversely impact our gross margins. Further, we may not achieve the anticipated improvements in manufacturing efficiency as we undertake actions to expand our manufacturing capacity. We are also subject to other general market and economic conditions that may increase our expenses, including unpredictable variability in commodity prices, wage increases and inflation. If we are unable to effectively manage our overall costs while increasing our production volumes and lowering our per-unit costs, we may not be able to achieve or sustain profitability, which would have an adverse impact on our business, financial condition and operating results.

Manufacturing risks may adversely affect our ability to manufacture products, which could negatively impact our sales and operating margins.

Our business strategy depends on our ability to manufacture our current and proposed products in sufficient quantities and on a timely basis to meet consumer demand, while adhering to product quality standards, complying with regulatory requirements and managing manufacturing costs. We are subject to numerous risks related to our manufacturing capabilities, including:

•quality or reliability defects in product components that we source from third-party suppliers;

•our inability to secure product components in a timely manner due to shipping delays at ports of entry or exit, the impact of natural disasters, global conflicts, health pandemics or other issues, in sufficient quantities and on commercially reasonable terms;

•difficulty identifying and qualifying alternative suppliers for components in a timely manner;

•implementing and maintaining acceptable quality systems while experiencing rapid growth;

•our failure to increase production of products to meet demand;

•our inability to modify production lines and expand manufacturing facilities to enable us to efficiently produce future products or implement changes in current products in response to consumer demand or regulatory requirements;

•our inability to manufacture multiple products simultaneously while utilizing common manufacturing equipment;

•government-mandated or voluntary closures of, or operational limitations impacting, our manufacturing facilities; and

•potential damage to or destruction of our manufacturing equipment or manufacturing facilities.

As demand for our products increases, and as the number of our commercial products expands, we will have to invest additional resources to purchase components, hire and train employees, and enhance our manufacturing processes and quality systems. We have also increased our use of third parties to perform contracted manufacturing services for us and failure in our oversight of these third parties or any disruption to their network business could negatively impact our business operations. We may also need to acquire additional custom designed equipment to support the expansion of our manufacturing capacity. In addition, although we expect some of our products under development to share product features and components with our current products, manufacturing of these products may require modifying our production lines, hiring specialized employees, identifying new suppliers for specific components, qualifying and implementing additional equipment and procedures, obtaining new regulatory clearances, certifications, or approvals, or developing new manufacturing technologies. Ultimately, it may not be possible for us to manufacture these products at a cost or in quantities sufficient to make these products commercially viable.

If we, our contract manufacturers, or our suppliers fail to increase our production capacity to meet consumer demand while also maintaining product quality standards, obtaining and maintaining regulatory clearances, certifications, or approvals, and efficiently managing costs, our sales and operating margins could be negatively impacted, which would have an adverse impact on our financial condition and operating results.

We depend on a limited number of third-party suppliers for certain components and products, and the loss of any of these suppliers, their inability to provide us with an adequate supply of components or products, or our inability to adequately forecast customer demand, could harm our business.

We currently rely, and expect to continue to rely, on third-party suppliers to supply components of our current products and our potential future products, including our single-use insulin cartridges. For example, we rely on plastic injection molding companies to provide plastic molded components, electronic manufacturing suppliers to provide electronic assemblies, and machining companies to provide machined mechanical components. We also purchase all of our infusion sets and pump accessories from third-party suppliers. For our business strategy to be successful, our suppliers must be able to provide us with components and products in sufficient quantities, in compliance with regulatory requirements and quality control standards, in accordance with agreed-upon specifications, at acceptable costs and on a timely basis.

Although we have long-term supply agreements with many of our suppliers, these agreements do not include long-term capacity commitments. Under most of our supply agreements, we make purchases on a purchase order basis and have no obligation to buy any given quantity of components or products until we place written orders, and our suppliers have no obligation to manufacture for us or sell to us any given quantity of components or products until they accept an order. In addition, our suppliers may encounter problems that limit their ability to manufacture components or products for us, including financial difficulties, damage to their manufacturing equipment or facilities, inability to obtain raw materials or other components, or problems with their own suppliers. If we fail to obtain sufficient quantities of high-quality components to meet demand on a timely basis, we could lose customer orders, our reputation may be harmed, and our business could suffer.

We generally use a small number of suppliers for our components and products, some of which are located internationally, including in China, Mexico and Costa Rica. Depending on a limited number of suppliers exposes us to risks, including limited control over costs, including tariffs, availability, quality and delivery schedules. Moreover, in some cases we do not have long-standing relationships with our manufacturers and may not be able to convince suppliers to continue to make components available to us unless there is demand for such components from their other customers. As a result, there is a risk that certain components could be discontinued and no longer available to us at acceptable prices, or at all. We have in the past been, and we may in the future be, required to make significant “last time” purchases of component inventories that are being discontinued by the manufacturer to ensure supply continuity. If any one or more of our suppliers cease to provide us with sufficient quantities of components in a timely manner or on terms acceptable to us, we would have to seek alternative sources of supply. We consistently evaluate alternative suppliers of several existing components and qualifying new alternatives to existing select components, but there is no assurance that we will be able to identify alternative sources that meet our requirements and at comparable prices, or at all. Because of factors such as the proprietary nature of our products, our quality control standards and applicable regulatory requirements, we cannot quickly engage additional or replacement suppliers for some of our critical components. Failure of any of our suppliers to deliver products at the level our business requires could harm our reputation and limit our ability to meet our sales projections, which could have a material adverse effect on our business, financial condition and operating results.

We place orders with our suppliers using our forecasts of customer demand, which are based on a number of assumptions and estimates, in advance of purchase commitments from our customers. As a result, we incur inventory and manufacturing costs in advance of anticipated sales, which sales ultimately may not materialize or may be lower than expected. If we overestimate customer demand, we may experience higher inventory carrying costs and increased excess or obsolete inventory, which would negatively impact our results of operations. By the same token, if we underestimate future demand, we may be unable to meet future production requirements, or our inventory of critical materials may be below our targeted stocking levels.

We may also have difficulty obtaining components from other suppliers that are acceptable to the FDA or other comparable foreign regulatory authorities, or Notified Bodies, and the failure of our suppliers to comply with regulatory requirements could expose us to regulatory action including warning letters, product recalls, termination or interruption of distribution, operating restrictions, product seizures, delays in obtaining approval or clearance of future products, suspension or withdrawal of approvals, clearances, or certification, fines, civil penalties, or criminal prosecution. Such a failure by our suppliers could also require us to cease using the components, seek alternative components or technologies, and modify our products to incorporate alternative components or technologies, which could necessitate additional regulatory clearances, certifications, or approvals. Any disruption of this nature, or any increased expenses associated with any such disruption, could negatively impact our ability to manufacture our products on a timely basis, in sufficient quantities, or at all, which could harm our commercialization efforts and have a material adverse impact on our operating results.

Any disruption at one of our facilities could adversely affect our business and operating results.

Although we operate in multiple locations, most of our current operations are still conducted in San Diego, California, including our final pump assembly, some manufacturing processes, and the majority of our research and development, management and administrative functions. In addition, the majority of our inventories of component supplies and finished goods is stored at two facilities in San Diego. We take precautions to safeguard our facilities and data infrastructure, including by acquiring insurance, employing back-up generators, adopting health and safety protocols, implementing cybersecurity protections, and utilizing off-site storage of computer data. However, vandalism, terrorism, unplanned power outages, cyberattacks or a natural disaster, such as an earthquake, fire or flood, or other catastrophic event, could damage or destroy our manufacturing equipment or our inventories of component supplies and finished goods, cause substantial delays in our operations, result in the loss of key information, result in reduced sales, and cause us to incur additional expenses. Our insurance coverage may not be sufficient to provide coverage with respect to the damages incurred in any particular case, and our insurance carrier may deny coverage with respect to all or a portion of our claims. Regardless of the level of insurance coverage or other precautions taken, damage to our facilities may have a material adverse effect on our business, financial condition and operating results.

We may not experience the anticipated operating efficiencies of our manufacturing and warehousing operations.

We continue to scale our business operations and add manufacturing requirements for products currently under development. We have outsourced the majority of our t:slim cartridge manufacturing demand to an experienced third-party contract manufacturer; we are in the process of moving our Tandem Mobi cartridge manufacturing to the same third-party contract manufacturer, and we are continually evaluating the outsourcing of other aspects of our operations. If we fail to achieve the operating efficiencies that we anticipate, our manufacturing and operating costs may be greater than expected, which would have a material adverse impact on our operating results. In addition, we or our third-party contract manufacturers may encounter problems during manufacturing for a variety of reasons, including failure to follow specific protocols and procedures, failure to comply with applicable regulations, equipment malfunction, component part supply constraints and environmental factors, any of which could delay or impede our ability to meet customer demand and have a material adverse impact on our business, financial condition and operating results. Further, because of the custom nature of our cartridge manufacturing process and product components, and the highly regulated nature of our products overall, in the event of any problems with a contract manufacturer, we may not be able to quickly establish additional or alternative arrangements.

We expect that the management and support of our facilities, increasing reliance on third-party contract manufacturers and the increase of our manufacturing volumes will place significant burdens on our management team, particularly in areas relating to operations, quality, regulatory, facilities and information technology. We may not be able to effectively manage our ongoing manufacturing operations and we may not achieve the operating efficiencies that we anticipate, either from our own facilities or from our use of contract manufacturing. Further, additional increases in demand for our products may require that we further expand our business operations, which may require that we obtain additional facilities, make additional investments in capital equipment or increase our use of third-party contract manufacturing.

We may enter into collaborations, licensing arrangements, joint ventures, strategic alliances or partnerships with third parties that may not result in the development of commercially viable products or the generation of significant future sales.

In the ordinary course of our business, we may enter into collaborations, licensing arrangements, joint ventures, strategic alliances or partnerships to develop proposed products or technologies, pursue new markets, or protect our intellectual property assets. We may also elect to amend or modify similar agreements that we already have in place. Proposing, negotiating and implementing collaborations, licensing arrangements, joint ventures, strategic alliances or partnerships may be a lengthy and complex process, and may subject us to business risks. For example, other companies, including those with substantially greater financial, marketing, sales, technology or other business resources, may compete with us for these opportunities, or may be the counterparty in any such arrangements. We may not be able to identify or complete any such collaboration in a timely manner, on a cost-effective basis, on acceptable terms or at all. In addition, we may not realize the anticipated benefits of any such collaborations that we do identify and complete. In particular, these collaborations may not result in the development of products or technologies that achieve commercial success or result in positive financial results or may otherwise fail to have the intended impact on our business.

Additionally, we may not be in a position to exercise sole decision-making authority regarding a collaboration, licensing or other similar arrangement, which could create the potential risk of creating impasses on decisions. Further, our collaborators and business partners may have economic or business interests or goals that are, or that may become, inconsistent with our business interests or goals. It is possible that conflicts may arise with our collaborators and other business partners, such as conflicts concerning the achievement of performance milestones, or the interpretation of significant terms under any agreement, such as those related to financial obligations, termination rights or the ownership or control or other licenses of intellectual property rights. If any conflicts arise with our current or future collaborators, they may act in their self-interest, which may be adverse to our best interest, and they may breach their obligations to us. In addition, we have limited control over the amount and timing of resources that our current collaborators, such as Dexcom and Abbott, or any future collaborators devote to our arrangement with them or our future products. Disputes between us and our current, future or potential collaborators may result in litigation or arbitration which would increase our expenses and divert the attention of our management. Further, these transactions and arrangements are contractual in nature and may be terminated or dissolved under the terms of the applicable agreements and, in such event, we may not continue to have rights to the products relating to such transaction or arrangement or may need to purchase such rights at a premium. For example, we have entered into multiple development and commercialization agreements with Dexcom, which have provided us non-exclusive licenses to integrate various generations of Dexcom’s CGM technology with our insulin pump products. Under certain circumstances, these agreements may be terminated by either party without cause or on short notice. Our current agreements with Dexcom do not grant us rights to integrate future generations of Dexcom CGM technology, beyond G7 CGM devices, with any of our current or future products. Termination of any of our agreements with Dexcom would require us to redesign certain current products and products under development, and would require us to integrate an alternative CGM system into our insulin pump systems in certain geographies, which would require significant development and regulatory activities that could result in an interruption or substantial delay in the availability of the product to our customers. The termination of our existing commercial agreements with Dexcom would disrupt our ability to commercialize our existing products and our development of future products, which could have a material adverse impact on our financial condition and results of operations and negatively impact our ability to compete.

Modifications to our business strategy or restructuring of our operations could lead to higher costs or otherwise impact the profitability of our business or the value of our assets.

As changes occur in our business environment, we have adjusted, and may continue to adjust, our business strategies, including our pursuit of a multi-channel managed care strategy to include offering our products through the pharmacy channel. We may also decide to further restructure our operations, specific business functions, or assets. However, any new structure and strategies may not deliver the expected benefits, such as supporting our growth objectives or enhancing shareholder value and could prove less effective than our previous approach. Additionally, external factors, including evolving technology, shifting consumer behaviors, acceptance of our products, and macroeconomic changes, could negatively impact the value of our assets. These changes or events may lead to costs associated with adjusting our business strategy and potentially necessitate writing down asset values.

Risks Related to Our International Operations

Commercializing our products internationally may result in a variety of risks associated with international operations that could materially adversely affect our business.

Our sales in more than 25 international countries where our products are offered, which accounted for approximately 30% of our total sales during 2025, are accompanied by certain financial and other risks related to international business markets, including:

•local product preferences and differing regulatory requirements for product clearances, certifications, or approvals;

•differing U.S. and foreign medical device import and export rules;

•more restrictive privacy and security laws relating to personal information of end-users and employees, including GDPR and other E.U. Member State national legislation;

•reduced protection for our intellectual property rights in certain international countries compared to the protection that exists in the United States;

•changes in tariffs, trade barriers and regulatory requirements;

•economic weakness, including inflation and workforce instability, and political instability in foreign economies and markets;

•compliance with tax, employment, immigration and labor laws, such as the Foreign Corrupt Practices Act and comparable foreign legislation;

•difficulties associated with foreign legal systems, including increased costs associated with enforcing contractual obligations in foreign jurisdictions;

•political instability and actual or anticipated military or political conflicts;

•difficulties in managing international relationships, including any relationships that we establish with foreign partners, distributors, or sales or marketing agents;

•foreign taxes, including withholding and payroll taxes;

•different reimbursement systems; and

•foreign currency fluctuations, which could result in increased operating expenses and reduced sales, and other obligations incident to doing business in another country.

In addition, entry into international markets may require significant financial resources, impose additional demands on our manufacturing, quality, regulatory, customer support and other general and administrative personnel, and could divert management’s attention from managing our core business. We have limited experience with regulatory environments and market practices internationally, and we may not be able to penetrate or successfully operate in new markets. If we are unable to expand internationally, effectively transition to direct sales in certain countries, manage the complexity of our global operations successfully or if we incur unanticipated expenses, we may not achieve the expected benefits of this expansion and our financial condition and results of operations could be materially and adversely impacted.

Failure to obtain any required regulatory authorization, clearance or certification in foreign jurisdictions will prevent us from marketing our products in international markets.

We sell our products in certain international countries and may seek to begin commercial sales of our products in additional geographies in the future. As we continue to expand our international operations and launch new products, we are increasingly subject to additional regulatory and legal requirements in the international markets. These additional legal and regulatory requirements may result in our incurring significant costs and expenditures. We have limited experience complying with applicable laws and regulations in international markets generally, and in particular when we enter new markets, and if we are not able to comply with any such requirements, our international expansion and business could be significantly harmed.

Failure to comply with the U.S. Foreign Corrupt Practices Act and similar worldwide anti-bribery laws could materially adversely affect our business and result in civil and/or criminal sanctions.

The FCPA, the U.K. Bribery Act, and similar anti-bribery laws enacted in other jurisdictions generally prohibit companies and their intermediaries from making improper payments to foreign officials for the purpose of obtaining or retaining business. Because of the predominance of government-sponsored healthcare systems around the world, most of our international customer relationships are with governmental entities and are therefore subject to such anti-bribery laws. Because we do business in the U.K., the U.K. Bribery Act also extends to our interaction with public and private sector entities and persons outside the U.K., including in the United States. Our policies mandate compliance with these anti-bribery laws. We operate in parts of the world that have experienced governmental corruption to some degree, and in certain circumstances strict compliance with anti-bribery laws may conflict with local customs and practices. Despite our training and compliance programs, our internal control policies and procedures may not always protect us from reckless or criminal acts committed by our employees or agents. Violations of anti-bribery laws, or allegations of such violations, could disrupt our business and have a material adverse effect on our results of operations, financial condition, and cash flows.

Risks Related to Our Indebtedness

We have incurred a significant amount of indebtedness, and the agreements governing such indebtedness subject us to required debt service payments, which may restrict our financial flexibility and affect our ability to operate our business.

From time to time, we have financed our liquidity needs under various credit arrangements and we may borrow additional funds in the future. For example, in March 2024, we completed the offering of $316.3 million aggregate principal amount of 1.50% Convertible Senior Notes due 2029 (the 2029 Notes), which are governed by the terms of an indenture (the indenture). In March 2024, we used the proceeds from the offering of the 2029 Notes to repurchase approximately $246.7 million aggregate principal amount of certain Convertible Senior Notes due 2025 (the 2025 Notes) in privately negotiated transactions with holders of the 2025 Notes and in the second quarter of 2025, all remaining 2025 Notes were paid in full. The 2029 Notes are our senior unsecured obligations, and interest on the 2029 Notes is payable in cash semi-annually at a rate of 1.50% per year.

Our failure to comply with certain obligations under the 2029 Notes, or inability to make required debt service payments, could result in an event of default under the indenture. A default, if not cured or waived, could result in acceleration of the indebtedness, which could have a material adverse effect on our business, financial condition and liquidity. Further, if our indebtedness is accelerated, we cannot be certain that cash will be available to pay the indebtedness and we may not have the ability to refinance the indebtedness on terms satisfactory to us or at all.

In addition, our current or future level of indebtedness could affect our business, operations and strategy in several important ways, including the following:

•we may be required to dedicate a portion of our current liquidity or cash flow from operations to interest payments, limiting the availability of cash for other purposes;

•covenants contained in future agreements governing indebtedness may limit our ability to borrow additional funds, refinance indebtedness or make certain investments;

•debt covenants may affect our flexibility in planning for, and reacting to, changes in the economy and our industry;

•a high level of indebtedness may increase our vulnerability to adverse economic and competitive conditions; and

•a high level of indebtedness may limit our ability to obtain additional financing in the future or negatively impact the terms on which additional financing may be obtained.

Servicing the 2029 Notes will require a significant amount of cash, and we may not have sufficient cash flow from our business to repay the 2029 Notes.

Our ability to make scheduled payments of the principal and interest on the 2029 Notes, or to refinance the 2029 Notes depends on our future business operations and liquidity, which are subject, to numerous risks and uncertainties, including, market acceptance of our products, regulatory clearance, certification, or approval for our products, and the competitive environment in which we operate. Our business may not generate or sustain a level of cash flow from operations sufficient to service the 2029 Notes and any future indebtedness we may incur. If we are unable to generate sufficient cash flow, we may be required to adopt one or more alternatives, such as reducing or delaying capital expenditures, selling or licensing assets, refinancing indebtedness, or obtaining additional equity capital. Our ability to successfully engage in these activities will depend on a number of factors, including the value of our assets, our operating results and financial condition, the value of our common stock, and the status of the capital markets at such time. We may not be able to engage in any of these activities on commercially reasonable terms or at all, which could result in a default under the 2029 Notes, or our future indebtedness.

In addition, we may from time to time seek to retire or purchase our outstanding debt, including the 2029 Notes, through cash purchases and/or exchanges for equity securities, in open market purchases, privately negotiated transactions or otherwise. Such repurchases or exchanges, if any, will depend on prevailing market conditions, our liquidity requirements, contractual restrictions, and other factors. The amounts involved in any such transactions, individually or in the aggregate, may be material. Further, any such purchases or exchanges may result in us acquiring and retiring a substantial amount of such indebtedness, which could impact the trading liquidity of such indebtedness.

We may not have sufficient cash or be able to obtain financing to repurchase the 2029 Notes upon a fundamental change, or to settle conversions of the 2029 Notes.

Holders of the 2029 Notes have the right to require us to repurchase their 2029 Notes upon the occurrence of a fundamental change (as defined in the indenture) at a repurchase price equal to 100% of the principal amount of the 2029 Notes to be repurchased, plus accrued and unpaid interest, if any. In addition, upon conversion of the 2029 Notes, unless we elect to deliver solely shares of our common stock to settle such conversion, we will be required to settle all or a portion of our conversion obligation through the payment of cash, which could adversely affect our liquidity. However, we may not have enough available cash or be able to obtain financing at the time we are required to make repurchases of the 2029 Notes or settle conversions of the 2029 Notes. In addition, our ability to repurchase the 2029 Notes or to pay cash upon conversions of the 2029 Notes may be limited by agreements governing our future indebtedness. Our failure to repurchase 2029 Notes at a time when the repurchase is required by the indenture, or to pay any cash payable on future conversions of the 2029 Notes as required by the indenture, would constitute an event of default under the indenture. A default under an indenture, or the fundamental change itself, could also lead to a default under agreements governing our existing or future indebtedness, including the other indenture. If the repayment of the related indebtedness were to be accelerated after any applicable notice or grace periods, we may not have sufficient funds to repay the indebtedness and repurchase the notes or make cash payments upon conversions thereof.

Conversion of the 2029 Notes will, to the extent we deliver shares upon conversion of such 2029 Notes, dilute the ownership interest of existing stockholders and may otherwise have a negative impact on the trading price of our common stock.

The conversion of some or all of the 2029 Notes will dilute the ownership interests of existing stockholders to the extent we deliver shares upon conversion of any of the 2029 Notes. Any sales in the public market of the common stock issued upon the conversion of the 2029 Notes could adversely affect prevailing market prices of our common stock. In addition, the perception that some or all of the 2029 Notes may be converted into shares of our common stock in the future could have a negative impact on the trading price of our common stock.

Certain provisions in the indentures governing the 2029 Notes may delay or prevent an otherwise beneficial takeover attempt.

Certain provisions in the indenture governing the 2029 Notes may make it more difficult or expensive for a third party to acquire us. For example, the terms of the 2029 Notes require us to offer to repurchase the 2029 Notes in the event of a fundamental change and, in certain circumstances, to increase the conversion rate for a holder that converts its 2029 Notes in connection with a make-whole fundamental change (as defined in the indenture governing the 2029 Notes). A takeover of the Company may trigger the requirement that we offer to repurchase the 2029 Notes and/or increase the conversion rate of the 2029 Notes for a holder that elects to convert its 2029 Notes, which could make it more costly for a potential acquirer to engage in such takeover. These and other provisions set forth in the indenture may have the effect of delaying or preventing a takeover of the Company that would otherwise be beneficial to investors.

The Capped Call Transactions may affect the value of the 2029 Notes and our common stock.

In connection with the issuance of the 2029 Notes, we entered into capped call transactions (the 2029 Capped Call Transactions) with certain financial institutions (the 2029 option counterparties). The 2029 Capped Call Transaction is expected generally to reduce the potential dilution to our common stock upon any conversion of the 2029 Notes and/or offset any cash payments we are required to make in excess of the principal amount of converted 2029 Notes, as the case may be, with such reduction and/or offset subject to a cap.

The 2029 option counterparties or their respective affiliates may modify their hedge positions by entering into or unwinding various derivatives with respect to our common stock and/or purchasing or selling our common stock or other securities of ours in secondary market transactions before the maturity of the 2029 Notes. This activity could also cause or avoid an increase or a decrease in the market price of our common stock or the 2029 Notes, which could affect a note holder’s ability to convert the 2029 Notes.

The potential effect, if any, of any of these transactions and activities on the market price of our common stock or the 2029 Notes will depend in part on market conditions and cannot be ascertained at this time, but any of these activities could adversely affect the value of our common stock and the value of the 2029 Notes and, under certain circumstances, the ability of the note holders to convert the 2029 Notes.

We are subject to counterparty risk with respect to the 2029 Capped Call Transactions.

The 2029 option counterparties are financial institutions, and we will be subject to the risk that any or all of them may default under the 2029 Capped Call Transactions. If a 2029 option counterparty becomes subject to insolvency proceedings, we will become an unsecured creditor in those proceedings with a claim equal to our exposure at that time under the 2029 Capped Call Transaction with such 2029 option counterparty. Our exposure will depend on many factors but, in general, an increase in our exposure will be correlated to an increase in the market price and volatility of our common stock. In addition, upon a default by a 2029 option counterparty, we may suffer more dilution than we currently anticipate with respect to our common stock.

Risks Related to Our Future Financings and Financial Results

We may need or otherwise determine to raise additional funds in the future and if we are unable to raise additional funds when necessary or desirable, we may not be able to achieve our strategic objectives.

As of December 31, 2025, we had $292.7 million in cash, cash equivalents and short-term investments. Our management expects the continued growth of our business, including the expansion of our customer service infrastructure to support our growing base of customers, our plans to continue expanding commercial sales of our products internationally, the growth of our manufacturing and warehousing operations, and the increase of our facility footprint to accommodate additional headcount and R&D activities, will continue to increase our expenses. In addition, the amount of our future product sales is difficult to predict and actual sales may not be in line with our forecasts. Accordingly, our future capital requirements will depend on many factors, including:

•revenue generated by sales of our products, as well as the gross profits and gross margin we realize from such sales;

•the costs associated with maintaining and expanding an appropriate sales, marketing, clinical and customer service infrastructure;

•expenses associated with developing and commercializing our proposed products or technologies, including capital expenditures we make to maintain or enhance our manufacturing operations and distribution capabilities;

•the cost of obtaining and maintaining regulatory clearance, certification, or approval for our products and our manufacturing facilities, and of ongoing compliance with other legal and regulatory requirements;

•expenses we incur in connection with current or future litigation or governmental investigations;

•expenses we may incur or other financial commitments we may make in connection with current and potential new acquisitions, investments, business or commercial collaborations, development agreements or licensing arrangements; and

•general and administrative expenses.

As a result of these and other factors we may in the future seek capital from public or private offerings of our equity or debt securities, or from other sources. If we issue equity or debt securities to raise additional funds, our existing stockholders may experience dilution, we may incur significant financing or debt service costs, and the new equity or debt securities may have rights, preferences and privileges senior to those of our existing stockholders. In addition, if we raise additional funds through collaborations, licensing, joint ventures, strategic alliances, partnership arrangements or other similar arrangements, it may be necessary to relinquish valuable rights to our potential future products or proprietary technologies, or grant licenses on terms that are not favorable to us.

If we are unable to raise additional capital when necessary, we may not be able to maintain our existing sales, marketing, clinical and customer service infrastructure, enhance our current products or develop new products, take advantage of future opportunities, respond to competitive pressures, changes in supplier relationships, or unanticipated changes in customer demand. Any of these events could adversely affect our ability to achieve our strategic objectives, which could have a material adverse effect on our business, financial condition and operating results.

Our operating results may fluctuate significantly from quarter to quarter.

TNDM US Equity

TNDM · 10-K · period ended 2025-12-31

Item 1. Business

Item 1A. Risk Factors.

TNDM US Equity☆

TNDM · 10-K · period ended 2025-12-31

Item 1. Business

Item 1A. Risk Factors.

TNDM US Equity