Organization and Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company Tandem Diabetes Care, a global insulin delivery and diabetes technology company, manufactures and sells advanced automated insulin delivery systems that reduce the burden of diabetes management, while creating new possibilities for patients, their loved ones and healthcare providers. Tandem Diabetes Care, Inc. is incorporated in the state of Delaware. Unless the context requires otherwise, the terms the “Company” or “Tandem” refer to Tandem Diabetes Care, Inc., together with its wholly-owned subsidiaries. The Company manufactures, sells, and supports insulin pump products that are designed to address the evolving needs and preferences of differentiated segments of the insulin-dependent diabetes market. The Company offers an insulin pump portfolio, which includes both the t:slim X2 and the Tandem Mobi. Both pumps feature Control-IQ+ technology, which is the Company’s advanced algorithm for managing insulin delivery, using information received from integrated continuous glucose monitoring (CGM) sensors. New software for the insulin pumps may be updated remotely by the individual users as new advancements become available and are compatible with other complementary digital health offerings, such as the Company’s mobile application and cloud-based diabetes management applications. The Company’s durable insulin pump products generally have an expected lifespan of at least four years. In addition to insulin pumps, the Company sells single-use components that are used together with the 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.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company has prepared the accompanying unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and pursuant to the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments which are of a normal and recurring nature and considered necessary for a fair presentation of the financial information contained herein have been included. Interim financial results are not necessarily indicative of results anticipated for the full year or any other period(s). These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 (Annual Report), from which the condensed consolidated balance sheet presented as of December 31, 2024 herein was derived. The condensed consolidated financial statements include the accounts of Tandem Diabetes Care, Inc. and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. The functional currency of the Company’s foreign subsidiaries is their respective local currency. The Company translates the financial statements of its foreign subsidiaries into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. Translation-related adjustments are included in other comprehensive income (loss) in the condensed consolidated statements of operations, and in accumulated other comprehensive income (loss) in the stockholders’ equity section of the Company’s condensed consolidated balance sheets. Foreign exchange gains or losses resulting from balances denominated in a currency other than the functional currency are recognized in interest income and other, net in the Company’s condensed consolidated statements of operations.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes as of the date of the condensed consolidated financial statements. Some of those judgments can be subjective and complex, and therefore, actual results could differ materially from those estimates under different assumptions or conditions.
Accounts Receivable	Accounts Receivable The Company grants credit to various customers in the ordinary course of business and is paid directly by customers who use its products, distributors and third-party insurance payors. The Company maintains an allowance for its current estimate of expected credit losses. Provisions for expected credit losses are estimated based on historical experience, assessment of specific customer-related risks, review of outstanding invoices, forecasts about the future, and various other assumptions and estimates that are believed to be reasonable under the circumstances, including changes to credit risks as a result of recessionary concerns, changes in discretionary spending, increased interest rates, and other macroeconomic factors. Uncollectible accounts are written off against the allowance after appropriate collection efforts have been exhausted and when it is deemed that a balance is uncollectible.
Operating Lease Right-of-Use Assets and Liabilities	Operating Lease Right-of-Use Assets and Liabilities Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized when the Company takes possession of the leased property (Commencement Date) based on the present value of lease payments over the lease term. For lease agreements that contain lease and non-lease components, the Company accounts for both of those components as a single lease component. Rent expense on noncancelable leases containing known future scheduled rent increases is recorded on a straight-line basis over the term of the respective leases beginning on the Commencement Date. The difference between rent expense and rent paid is accounted for as a component of operating lease right-of-use assets on the Company’s condensed consolidated balance sheets. Landlord improvement allowances and other similar lease incentives are recorded as a reduction of the right-of-use leased assets, and are amortized on a straight-line basis as a reduction to operating lease costs.
Intangible Assets Subject to Amortization	Intangible Assets Subject to Amortization Finite-lived intangible assets are recorded at cost, net of accumulated amortization and, if applicable, impairment charges. Amortization of finite-lived intangible assets is recognized over their estimated useful lives on a straight-line basis.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, such as property and equipment, right-of-use lease assets, and acquired intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying amount. If the carrying amount of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. Fair value is determined using unobservable (Level 3) inputs, including discounted cash flow models, future estimated sublease income, and third-party independent appraisals, as considered necessary. There is uncertainty in the projected undiscounted future cash flows used in the Company’s impairment review analysis, which requires the use of estimates and assumptions. If actual performance does not meet or exceed projected performance, or if the assumptions used in the model change in the future, the Company may be required to recognize additional impairment charges in future periods. Other than the impairment of operating lease right-of-use assets recognized in the first half of 2025 (see Note 6, “Leases”), there were no other impairments of long-lived assets, including acquired intangible assets, during the three and six months ended June 30, 2025 and 2024.
Equity Method Investments	Equity Method Investments The Company held equity method investments of $67.6 million and $74.5 million at June 30, 2025 and December 31, 2024, respectively. The Company uses the equity method to account for investments in companies if it owns more than 20% of the investee company’s outstanding equity or the investment provides the Company with the ability to exercise significant influence but not control over the operating and financial policies of the investee. The Company assesses whether it has significant influence by considering various factors, including the nature and magnitude of the investment, voting rights held and participation in the governance of the investee, if any. The Company may also consider additional relevant factors, such as the presence of other business relationships. The Company’s condensed consolidated net loss included its proportionate share of the net loss of its equity method investee, which was $3.4 million and $6.9 million for the three and six months ended June 30, 2025, respectively. For the three and six months ended June 30, 2024, the Company did not hold any equity method investments and therefore did not recognize a share of net income or loss from any equity method investments.
Revenue Recognition	Revenue Recognition Revenue is generated primarily from sales of insulin pumps, single-use insulin cartridges and infusion sets to individual customers with third-party insurance coverage and through a network of distributors that resell the products to insulin-dependent diabetes customers. The Company recognizes revenue when it transfers control of the promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services, net of estimated rebates, prompt payment discounts and a provision for product returns. Revenue Recognition for Arrangements with Multiple Performance Obligations The Company considers the individual deliverables in its product offerings to be separate performance obligations. The transaction price is determined based on the net consideration to which the Company expects to be entitled, based either on the stated value in contractual arrangements or the estimated cash to be collected in non-contracted arrangements. The Company includes an estimate of variable consideration in the calculation of the transaction price at the time of sale. Variable consideration includes, but is not limited to: rebates, prompt payment discounts and a provision for product returns. The Company classifies these items as a reduction of accounts receivable when it is not required to make a payment and as a liability when it is required to make a payment. The Company allocates the consideration to the individual performance obligations and recognizes the consideration based on when the performance obligation is satisfied, considering whether or not this occurs at a point in time or over time. Generally, insulin pumps, cartridges, infusion sets, and accessories are deemed performance obligations that are satisfied at a point in time when the customer obtains control of the promised good, which typically is upon shipment for our distributor arrangements and upon receipt for sales directly to individual customers. Complementary products, such as the Company’s data management and software update platforms, are considered distinct performance obligations that are satisfied over time, as access and support for these products is provided throughout the typical four-year warranty period of the insulin pumps. Accordingly, revenue related to the complementary products is deferred and recognized over a four-year period. Where there is no standalone value for the complementary product, the Company determines its value by applying the expected cost plus a margin approach and then allocates the residual to the insulin pumps. Variable Consideration The amount of variable consideration that is included in the transaction price is included in revenue only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. The Company is subject to certain rebates on pricing programs with managed care organizations, such as pharmacy benefit managers and governmental and third-party commercial payors, and may vary by customer. The Company estimates provisions for rebates based on contractual arrangements, estimates of products sold subject to rebate, known market events or trends and channel inventory data. Estimated sales rebates included in other long-term liabilities have an estimated payment due date beyond twelve months from the balance sheet date. Accordingly, actual rebates paid may differ from estimated amounts recorded in the accompanying consolidated financial statements. Revenue Recognition for Tandem Choice Program From September 2022 to December 31, 2024, the Company offered a technology access program referred to as Tandem Choice that provided eligible in-warranty t:slim X2 customers in the United States with the flexibility to obtain the Tandem Mobi, once commercially available. The Company determined that the program created a material right for which a portion of each t:slim X2 pump sales transaction price was allocated and deferred. The Company began selling Tandem Mobi insulin pumps in February 2024 and eligibility for the Tandem Choice program ended at that time. Consequently, the Company ceased allocating and deferring a portion of the transaction price for the material right for pumps sold after that date. Eligible customers who purchased a t:slim X2 insulin pump during the program period had until December 31, 2024 to exercise the option to switch to the Tandem Mobi for a stated fee. The Company recognized the deferred sales when the obligations under the Tandem Choice program were satisfied. If a customer elected to participate in the program, the Company recognized upgrade fees received, and the associated cost of goods sold, at the time of fulfillment. The remaining deferrals were recognized at program expiration on December 31, 2024. For the six months ended June 30, 2024, the Company deferred $1.1 million of pump sales as the result of Tandem Choice, and recognized incremental sales of $0.2 million from individual Tandem Choice fulfillments. There was no comparative adjustment to pump sales in 2025.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company records the fair value of derivative instruments as either current assets or current liabilities on the condensed consolidated balance sheets. Changes in the fair value of derivative instruments are recorded each period in current earnings or other comprehensive income (loss), depending on whether a derivative instrument is designated as part of a hedging transaction. For a derivative to qualify as a hedge at inception and throughout the hedged period, the Company formally documents the nature and relationships between the hedging instrument and hedged item. For derivatives formally designated as hedges, the Company assesses both at inception and quarterly thereafter, whether the hedging derivatives are highly effective in offsetting changes in either the fair value or cash flows of the hedged item. Gains or losses on cash flow hedges are reclassified from other comprehensive income (loss) to earnings when the hedged transaction occurs and affects consolidated results. If the Company determines that a forecasted transaction is no longer probable of occurring, the Company discontinues hedge accounting and any related unrealized gain or loss on the derivative instrument is recognized in current earnings. Derivatives that are not designated and do not qualify as hedges are adjusted to fair value through current earnings.
Warranty Reserve	Warranty Reserve The Company generally provides a four-year warranty on its insulin pumps to end-user customers and may replace any pumps that do not function as intended in accordance with the product specifications within the warranty period. In addition, the Company offers a six-month warranty on single-use insulin cartridges and infusion sets. Estimated warranty costs are recorded at the time of shipment, and the Company reevaluates the estimate of the warranty reserve obligation at each reporting period. Warranty costs are primarily estimated based on the current expected product replacement cost and expected replacement rates using historical experience. Returned insulin pumps may be refurbished and redeployed. Experience has shown that initial data for any new pump version or pump platform may be insufficient. Therefore, the Company relies on long-term historical replacement data from existing platforms until sufficient data is available. As actual experience accumulates, the Company adjusts its warranty reserve estimate accordingly. In addition, the availability of replacement data may differ by country due to local compliance and privacy regulations, which may require the Company to estimate its warranty liability using available information or data from similar markets. The Company may make further adjustments to the warranty reserve when appropriate, considering revised expectations of product performance based on enhanced hardware, or new features and capabilities that may become available through Tandem Device Updater. Warranty expense is recorded as a component of cost of sales in the consolidated statements of operations.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation cost is measured at the grant date based on the estimated fair value of the award, and the portion that is ultimately expected to vest is recognized as compensation expense over the requisite service period on a straight-line basis. The Company estimates the fair value of stock options issued under the Company’s stock incentive plans, and the fair value of employee purchase rights under the Company’s Employee Stock Purchase Plan (ESPP) using the Black-Scholes option pricing model on the date of grant. The Black-Scholes option pricing model requires the use of assumptions about a number of variables, including stock price volatility, expected term, dividend yield and risk-free interest rate (see Note 8, “Stockholders’ Equity”). The fair value of restricted stock unit (RSU) awards issued under the Company’s stock incentive plans that vest solely based on service, is estimated based on the fair market value of the underlying stock on the date of grant. The fair value of RSU awards that vest based upon the Company’s actual performance relative to predefined performance metrics and the awardee’s continuing service through the measurement date is generally estimated based on the fair market value of the underlying stock on the date of grant and the probability that the specified performance criteria will be met. At each reporting period, the Company reassesses the probability of the achievement of such performance metrics. Any expense change resulting from an adjustment in the estimated shares to be released is recorded in the period of adjustment.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share reflects the potential dilution that would occur if securities exercisable for or convertible into common stock were exercised for or converted into common stock. Dilutive common share equivalents are comprised of stock options and unvested RSUs outstanding under the Company’s stock incentive plans, potential awards to be granted pursuant to the ESPP, and common stock warrants, each calculated using the treasury stock method, and shares issuable upon conversion of the convertible senior notes calculated using the if-converted method.
Recently Issued Accounting Pronouncements and Accounting Pronouncements Issued and Not Yet Adopted	Recently Issued Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires the Company to disclose disaggregated jurisdictional and categorical information for the tax rate reconciliation, income taxes paid and other income tax related amounts. The guidance is effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating ASU 2023-09 to determine the impact it may have on its consolidated financial statements. Accounting Pronouncements Issued and Not Yet Adopted In November 2024, the FASB issued ASU 2024-03 Income Statement–Reporting Comprehensive Income–Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which requires entities to disclose information about purchases of inventory, employee compensation, and intangible asset amortization in each income statement line item that contains those expenses. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating ASU 2024-03 to determine the impact it may have on its consolidated financial statements.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses, and employee-related liabilities are reasonable estimates of their fair values because of the short-term nature of these assets and liabilities. Short-term investments are carried at fair value.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker (CODM) in making decisions regarding resource allocation and assessing performance. The Company is organized based on its current product portfolio, which consists primarily of insulin pumps, single-use insulin cartridges and infusion sets for the storage and delivery of insulin. The Company views its operations and manages its business as one reporting segment because key operating decisions and resource allocations are made by the CODM using consolidated financial data. Accordingly, the Company is organized as a single operating segment and therefore a single reportable segment: Insulin Pumps and Supplies. The Company’s CODM is the Chief Executive Officer (CEO), who evaluates segment performance based on segment net income (loss) on a consolidated basis. Segment net income (loss) was consistent with the net loss amounts reported in the Company’s condensed consolidated statement of operations and comprehensive loss for the three and six months ended June 30, 2025 and 2024. There were no significant segment expenses that are regularly provided to the CODM other than those reported in the Company’s condensed consolidated statement of operations and comprehensive loss for the three and six months ended June 30, 2025 and 2024. The Company’s CODM is provided segment assets information on a consolidated basis for the evaluation of Company performance. Total segment assets were consistent with total assets reported in the Company’s condensed consolidated balance sheets for June 30, 2025 and December 31, 2024.

Organization and Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Tandem Diabetes Care, a global insulin delivery and diabetes technology company, manufactures and sells advanced automated insulin delivery systems that reduce the burden of diabetes management, while creating new possibilities for patients, their loved ones and healthcare providers. Tandem Diabetes Care, Inc. is incorporated in the state of Delaware. Unless the context requires otherwise, the terms the “Company” or “Tandem” refer to Tandem Diabetes Care, Inc., together with its wholly-owned subsidiaries.

The Company manufactures, sells, and supports insulin pump products that are designed to address the evolving needs and preferences of differentiated segments of the insulin-dependent diabetes market. The Company offers an insulin pump portfolio, which includes both the t:slim X2 and the Tandem Mobi. Both pumps feature Control-IQ+ technology, which is the Company’s advanced algorithm for managing insulin delivery, using information received from integrated continuous glucose monitoring (CGM) sensors. New software for the insulin pumps may be updated remotely by the individual users as new advancements become available and are compatible with other complementary digital health offerings, such as the Company’s mobile application and cloud-based diabetes management applications. The Company’s durable insulin pump products generally have an expected lifespan of at least four years. In addition to insulin pumps, the Company sells single-use components that are used together with the 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.

Basis of Presentation and Principles of Consolidation

The Company has prepared the accompanying unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and pursuant to the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments which are of a normal and recurring nature and considered necessary for a fair presentation of the financial information contained herein have been included.

Interim financial results are not necessarily indicative of results anticipated for the full year or any other period(s). These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 (Annual Report), from which the condensed consolidated balance sheet presented as of December 31, 2024 herein was derived. The condensed consolidated financial statements include the accounts of Tandem Diabetes Care, Inc. and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

The functional currency of the Company’s foreign subsidiaries is their respective local currency. The Company translates the financial statements of its foreign subsidiaries into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. Translation-related adjustments are included in other comprehensive income (loss) in the condensed consolidated statements of operations, and in accumulated other comprehensive income (loss) in the stockholders’ equity section of the Company’s condensed consolidated balance sheets. Foreign exchange gains or losses resulting from balances denominated in a currency other than the functional currency are recognized in interest income and other, net in the Company’s condensed consolidated statements of operations.

Use of Estimates

The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes as of the date of the condensed consolidated financial statements. Some of those judgments can be subjective and complex, and therefore, actual results could differ materially from those estimates under different assumptions or conditions.

Accounts Receivable

The Company grants credit to various customers in the ordinary course of business and is paid directly by customers who use its products, distributors and third-party insurance payors. The Company maintains an allowance for its current estimate of expected credit losses. Provisions for expected credit losses are estimated based on historical experience, assessment of specific customer-related risks, review of outstanding invoices, forecasts about the future, and various other assumptions and estimates that are believed to be reasonable under the circumstances, including changes to credit risks as a result of recessionary concerns, changes in discretionary spending, increased interest rates, and other macroeconomic factors. Uncollectible accounts are written off against the allowance after appropriate collection efforts have been exhausted and when it is deemed that a balance is uncollectible.

Operating Lease Right-of-Use Assets and Liabilities

Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized when the Company takes possession of the leased property (Commencement Date) based on the present value of lease payments over the lease term. For lease agreements that contain lease and non-lease components, the Company accounts for both of those components as a single lease component. Rent expense on noncancelable leases containing known future scheduled rent increases is recorded on a straight-line basis over the term of the respective leases beginning on the Commencement Date. The difference between rent expense and rent paid is accounted for as a component of operating lease right-of-use assets on the Company’s condensed consolidated balance sheets. Landlord improvement allowances and other similar lease incentives are recorded as a reduction of the right-of-use leased assets, and are amortized on a straight-line basis as a reduction to operating lease costs.

Intangible Assets Subject to Amortization

Finite-lived intangible assets are recorded at cost, net of accumulated amortization and, if applicable, impairment charges. Amortization of finite-lived intangible assets is recognized over their estimated useful lives on a straight-line basis.

Impairment of Long-Lived Assets

Long-lived assets, such as property and equipment, right-of-use lease assets, and acquired intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying amount. If the carrying amount of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. Fair value is determined using unobservable (Level 3) inputs, including discounted cash flow models, future estimated sublease income, and third-party independent appraisals, as considered necessary. There is uncertainty in the projected undiscounted future cash flows used in the Company’s impairment review analysis, which requires the use of estimates and assumptions. If actual performance does not meet or exceed projected performance, or if the assumptions used in the model change in the future, the Company may be required to recognize additional impairment charges in future periods. Other than the impairment of operating lease right-of-use assets recognized in the first half of 2025 (see Note 6, “Leases”), there were no other impairments of long-lived assets, including acquired intangible assets, during the three and six months ended June 30, 2025 and 2024.

Equity Method Investments

The Company held equity method investments of $67.6 million and $74.5 million at June 30, 2025 and December 31, 2024, respectively. The Company uses the equity method to account for investments in companies if it owns more than 20% of the investee company’s outstanding equity or the investment provides the Company with the ability to exercise significant influence but not control over the operating and financial policies of the investee. The Company assesses whether it has significant influence by considering various factors, including the nature and magnitude of the investment, voting rights held and participation in the governance of the investee, if any. The Company may also consider additional relevant factors, such as the presence of other business relationships.

The Company’s condensed consolidated net loss included its proportionate share of the net loss of its equity method investee, which was $3.4 million and $6.9 million for the three and six months ended June 30, 2025, respectively. For the three and six months ended June 30, 2024, the Company did not hold any equity method investments and therefore did not recognize a share of net income or loss from any equity method investments.

Revenue Recognition

Revenue is generated primarily from sales of insulin pumps, single-use insulin cartridges and infusion sets to individual customers with third-party insurance coverage and through a network of distributors that resell the products to insulin-dependent diabetes customers. The Company recognizes revenue when it transfers control of the promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services, net of estimated rebates, prompt payment discounts and a provision for product returns.

Revenue Recognition for Arrangements with Multiple Performance Obligations

The Company considers the individual deliverables in its product offerings to be separate performance obligations. The transaction price is determined based on the net consideration to which the Company expects to be entitled, based either on the stated value in contractual arrangements or the estimated cash to be collected in non-contracted arrangements. The Company includes an estimate of variable consideration in the calculation of the transaction price at the time of sale. Variable consideration includes, but is not limited to: rebates, prompt payment discounts and a provision for product returns. The Company classifies these items as a reduction of accounts receivable when it is not required to make a payment and as a liability when it is required to make a payment.

The Company allocates the consideration to the individual performance obligations and recognizes the consideration based on when the performance obligation is satisfied, considering whether or not this occurs at a point in time or over time. Generally, insulin pumps, cartridges, infusion sets, and accessories are deemed performance obligations that are satisfied at a point in time when the customer obtains control of the promised good, which typically is upon shipment for our distributor arrangements and upon receipt for sales directly to individual customers. Complementary products, such as the Company’s data management and software update platforms, are considered distinct performance obligations that are satisfied over time, as access and support for these products is provided throughout the typical four-year warranty period of the insulin pumps. Accordingly, revenue related to the complementary products is deferred and recognized over a four-year period. Where there is no standalone value for the complementary product, the Company determines its value by applying the expected cost plus a margin approach and then allocates the residual to the insulin pumps.

Variable Consideration

The amount of variable consideration that is included in the transaction price is included in revenue only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. The Company is subject to certain rebates on pricing programs with managed care organizations, such as pharmacy benefit managers and governmental and third-party commercial payors, and may vary by customer. The Company estimates provisions for rebates based on contractual arrangements, estimates of products sold subject to rebate, known market events or trends and channel inventory data. Estimated sales rebates included in other long-term liabilities have an estimated payment due date beyond twelve months from the balance sheet date. Accordingly, actual rebates paid may differ from estimated amounts recorded in the accompanying consolidated financial statements.

Revenue Recognition for Tandem Choice Program

From September 2022 to December 31, 2024, the Company offered a technology access program referred to as Tandem Choice that provided eligible in-warranty t:slim X2 customers in the United States with the flexibility to obtain the Tandem Mobi, once commercially available. The Company determined that the program created a material right for which a portion of each t:slim X2 pump sales transaction price was allocated and deferred. The Company began selling Tandem Mobi insulin pumps in February 2024 and eligibility for the Tandem Choice program ended at that time. Consequently, the Company ceased allocating and deferring a portion of the transaction price for the material right for pumps sold after that date. Eligible customers who purchased a t:slim X2 insulin pump during the program period had until December 31, 2024 to exercise the option to switch to the Tandem Mobi for a stated fee.

The Company recognized the deferred sales when the obligations under the Tandem Choice program were satisfied. If a customer elected to participate in the program, the Company recognized upgrade fees received, and the associated cost of goods sold, at the time of fulfillment. The remaining deferrals were recognized at program expiration on December 31, 2024. For the six months ended June 30, 2024, the Company deferred $1.1 million of pump sales as the result of Tandem Choice, and recognized incremental sales of $0.2 million from individual Tandem Choice fulfillments. There was no comparative adjustment to pump sales in 2025.

Derivative Instruments and Hedging Activities

The Company records the fair value of derivative instruments as either current assets or current liabilities on the condensed consolidated balance sheets. Changes in the fair value of derivative instruments are recorded each period in current earnings or other comprehensive income (loss), depending on whether a derivative instrument is designated as part of a hedging transaction. For a derivative to qualify as a hedge at inception and throughout the hedged period, the Company formally documents the nature and relationships between the hedging instrument and hedged item.

For derivatives formally designated as hedges, the Company assesses both at inception and quarterly thereafter, whether the hedging derivatives are highly effective in offsetting changes in either the fair value or cash flows of the hedged item.

Gains or losses on cash flow hedges are reclassified from other comprehensive income (loss) to earnings when the hedged transaction occurs and affects consolidated results. If the Company determines that a forecasted transaction is no longer probable of occurring, the Company discontinues hedge accounting and any related unrealized gain or loss on the derivative instrument is recognized in current earnings.

Derivatives that are not designated and do not qualify as hedges are adjusted to fair value through current earnings.

Warranty Reserve

The Company generally provides a four-year warranty on its insulin pumps to end-user customers and may replace any pumps that do not function as intended in accordance with the product specifications within the warranty period. In addition, the Company offers a six-month warranty on single-use insulin cartridges and infusion sets. Estimated warranty costs are recorded at the time of shipment, and the Company reevaluates the estimate of the warranty reserve obligation at each reporting period. Warranty costs are primarily estimated based on the current expected product replacement cost and expected replacement rates using historical experience. Returned insulin pumps may be refurbished and redeployed.

Experience has shown that initial data for any new pump version or pump platform may be insufficient. Therefore, the Company relies on long-term historical replacement data from existing platforms until sufficient data is available. As actual experience accumulates, the Company adjusts its warranty reserve estimate accordingly. In addition, the availability of replacement data may differ by country due to local compliance and privacy regulations, which may require the Company to estimate its warranty liability using available information or data from similar markets. The Company may make further adjustments to the warranty reserve when appropriate, considering revised expectations of product performance based on enhanced hardware, or new features and capabilities that may become available through Tandem Device Updater. Warranty expense is recorded as a component of cost of sales in the consolidated statements of operations.

Stock-Based Compensation

Stock-based compensation cost is measured at the grant date based on the estimated fair value of the award, and the portion that is ultimately expected to vest is recognized as compensation expense over the requisite service period on a straight-line basis. The Company estimates the fair value of stock options issued under the Company’s stock incentive plans, and the fair value of employee purchase rights under the Company’s Employee Stock Purchase Plan (ESPP) using the Black-Scholes option pricing model on the date of grant. The Black-Scholes option pricing model requires the use of assumptions about a number of variables, including stock price volatility, expected term, dividend yield and risk-free interest rate (see Note 8, “Stockholders’ Equity”). The fair value of restricted stock unit (RSU) awards issued under the Company’s stock incentive plans that vest solely based on service, is estimated based on the fair market value of the underlying stock on the date of grant. The fair value of RSU awards that vest based upon the Company’s actual performance relative to predefined performance metrics and the awardee’s continuing service through the measurement date is generally estimated based on the fair market value of the underlying stock on the date of grant and the probability that the specified performance criteria will be met. At each reporting period, the Company reassesses the probability of the achievement of such performance metrics. Any expense change resulting from an adjustment in the estimated shares to be released is recorded in the period of adjustment.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share reflects the potential dilution that would occur if securities exercisable for or convertible into common stock were exercised for or converted into common stock. Dilutive common share equivalents are comprised of stock options and unvested RSUs outstanding under the Company’s stock incentive plans, potential awards to be granted pursuant to the ESPP, and common stock warrants, each calculated using the treasury stock method, and shares issuable upon conversion of the convertible senior notes calculated using the if-converted method.

Recently Issued Accounting Pronouncements and Accounting Pronouncements Issued and Not Yet Adopted

Recently Issued Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires the Company to disclose disaggregated jurisdictional and categorical information for the tax rate reconciliation, income taxes paid and other income tax related amounts. The guidance is effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating ASU 2023-09 to determine the impact it may have on its consolidated financial statements.

Accounting Pronouncements Issued and Not Yet Adopted

In November 2024, the FASB issued ASU 2024-03 Income Statement–Reporting Comprehensive Income–Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which requires entities to disclose information about purchases of inventory, employee compensation, and intangible asset amortization in each income statement line item that contains those expenses. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating ASU 2024-03 to determine the impact it may have on its consolidated financial statements.

Fair Value of Financial Instruments

The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses, and employee-related liabilities are reasonable estimates of their fair values because of the short-term nature of these assets and liabilities. Short-term investments are carried at fair value.

Segment Reporting

Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker (CODM) in making decisions regarding resource allocation and assessing performance. The Company is organized based on its current product portfolio, which consists primarily of insulin pumps, single-use insulin cartridges and infusion sets for the storage and delivery of insulin. The Company views its operations and manages its business as one reporting segment because key operating decisions and resource allocations are made by the CODM using consolidated financial data. Accordingly, the Company is organized as a single operating segment and therefore a single reportable segment: Insulin Pumps and Supplies.

The Company’s CODM is the Chief Executive Officer (CEO), who evaluates segment performance based on segment net income (loss) on a consolidated basis. Segment net income (loss) was consistent with the net loss amounts reported in the Company’s condensed consolidated statement of operations and comprehensive loss for the three and six months ended June 30, 2025 and 2024. There were no significant segment expenses that are regularly provided to the CODM other than those reported in the Company’s condensed consolidated statement of operations and comprehensive loss for the three and six months ended June 30, 2025 and 2024.

The Company’s CODM is provided segment assets information on a consolidated basis for the evaluation of Company performance. Total segment assets were consistent with total assets reported in the Company’s condensed consolidated balance sheets for June 30, 2025 and December 31, 2024.