Biggest changeAs of December 31, 2023, we did not have any off-balance sheet arrangements that have, or are reasonably likely to have, a current or future material effect on our financial condition, results of operations, liquidity, capital expenditures or capital resources. 87 Table of Contents Cash Flows The following table presents a summary of our cash flow for the periods indicated: Year Ended December 31, 2023 2022 (in thousands) Net cash provided by (used in): Operating activities $ 24,653 $ 11,569 Investing activities (294,822) (19,596) Financing activities 13,950 235,077 Effect of exchange rate on cash 164 75 (Decrease) increase in cash and cash equivalents $ (256,055) $ 227,125 Operating Activities Net cash provided by operating activities was $24.7 million for 2023 and consisted of a net loss of $21.2 million, non-cash charges of $86.6 million, and a decrease in net operating assets of $40.8 million.
Biggest changeSee section titled “Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities” in Part II, Item 5 of this report for stock repurchases during the quarter ended December 31, 2024 and Note 6 of our Notes to our Consolidated Financial Statements for further details regarding our Repurchase Program. 83 Table of Contents Cash Flows The following table presents a summary of our cash flow for the periods indicated: Year Ended December 31, 2024 2023 (in thousands) Net cash provided by (used in): Operating activities $ 130,246 $ 24,653 Investing activities (113,122) (294,822) Financing activities (52,393) 13,950 Effect of exchange rate on cash (118) 164 Decrease in cash and cash equivalents $ (35,387) $ (256,055) Operating Activities Net cash provided by operating activities was $130.2 million for 2024 and consisted of net income of $53.5 million, non-cash charges of $114.4 million, and a decrease in net operating assets of $37.7 million.
In addition, we highlight our compelling clinical data and value proposition to increase awareness and adoption amongst referring physicians. We build upon this top-down approach with strong direct-to-consumer marketing initiatives to create awareness of the benefits of our Inspire system and drive interest through patient empowerment. This outreach helps to educate thousands of patients on our Inspire therapy.
In addition, we highlight our compelling clinical data and value proposition to increase awareness and adoption amongst referring physicians. We build upon this top-down approach with strong direct-to-consumer marketing initiatives to create awareness of the benefits of our Inspire system and drive interest through patient empowerment. We believe this outreach helps to educate thousands of patients on our Inspire therapy.
We sell our Inspire system to hospitals and ambulatory surgery centers ("ASCs") in the U.S. and in select countries in Europe and Japan through a direct sales organization and we sell our Inspire system in Singapore and Hong Kong through distributors. Our direct sales force engages in sales efforts and promotional activities focused on ENT physicians and sleep centers.
We sell our Inspire system to hospitals and ambulatory surgery centers ("ASCs") in the U.S. and in select countries in Europe and Japan through a direct sales organization and we sell our Inspire system in Singapore and Hong Kong through distributors. Our direct sales force engages in sales efforts and promotional activities primarily focused on ENT physicians and sleep centers.
In the U.S., our products are shipped directly to our U.S. customers and to our Singapore and Hong Kong distributors on a purchase order basis, primarily by a third-party vendor with a facility in Tennessee, although we do ship some products from our facility in Minnesota.
Our products are shipped directly to our U.S. customers and to our Singapore and Hong Kong distributors on a purchase order basis, primarily by a third-party vendor with a facility in Tennessee, although we do ship some products from our facility in Minnesota.
There can be no assurance that such transactions will be available to us on favorable terms, if at all. Below is a summary of short-term and long-term anticipated cash requirements under contractual obligations existing as of December 31, 2023.
There can be no assurance that such transactions will be available to us on favorable terms, if at all. Below is a summary of short-term and long-term anticipated cash requirements under contractual obligations existing as of December 31, 2024.
During the fourth quarter of 2023 and extending into early 2024, the delay in certification and the shortage of polyurethane-based stimulation leads caused delays to implant procedures which adversely affected our business in the EU, including a reduction in our European revenue, and thereby our consolidated revenue.
During the fourth quarter of 2023 and extending into early 2024, the delay in certification and the shortage of polyurethane-based stimulation leads caused delays to implant procedures which adversely affected our business in Europe, including a reduction in our European revenue, and thereby our consolidated revenue.
Investing activities also included purchases of property and equipment of $23.6 million, mainly for testing systems and production equipment for our next generation Inspire system, our SleepSync™ platform, computer hardware and software, and leasehold improvements, as well as the purchase of strategic investments of $0.3 million.
Investing activities also included purchases of property and equipment of $23.6 million, mainly for testing systems and manufacturing equipment for our next generation Inspire system, our SleepSync™ platform, computer hardware and software, and leasehold improvements, as well as the purchase of strategic investments of $0.3 million.
Higher interest rates and capital costs, higher shipping costs, increased costs of labor, international conflicts and terrorism, and weakening foreign currency exchange rates are creating additional economic challenges. These conditions may cause our customers to decrease or delay orders for our products.
Higher interest rates and capital costs, higher shipping costs and new or increased tariffs, increased costs of labor, international conflicts and terrorism, and weakening foreign currency exchange rates are creating additional economic challenges. These conditions may cause our customers to decrease or delay orders for our products.
As noted above, during the fourth quarter of 2023, not having received EU MDR certification of our silicone-based stimulation lead and the resulting shortage of polyurethane-based stimulation leads had an estimated adverse impact on European revenue of approximately $4 million.
As noted above, during the fourth quarter of 2023, not having received EU MDR certification of our silicone-based stimulation lead and the resulting shortage of polyurethane-based stimulation leads had an estimated adverse impact on European revenue during that period of approximately $4.0 million.
We continue to make investments in research and development efforts to develop our next generation Inspire systems and support our future regulatory submissions for expanded indications and for new markets such as additional European countries and the Asia Pacific region.
We continue to make investments in research and development efforts to develop our next generations of the Inspire systems and support our future regulatory submissions for expanded indications and for new markets such as additional European countries and the Asia Pacific region.
We expect research and development expenses to increase in the future as we develop next generation versions of our Inspire system and SleepSync™ and continue to expand our clinical studies to further expand positive coverage policies from private commercial payors in the U.S. and enter into new markets including additional European countries and the Asia Pacific region.
We expect R&D expenses to increase in the future as we develop next generation versions of our Inspire system and SleepSync™ and continue to expand our clinical studies to further expand positive coverage policies from private commercial payors in the U.S. and enter into new markets including additional European countries and the Asia Pacific region.
We believe that our existing cash and cash equivalents and available for sale investments, which totaled $469.5 million as of December 31, 2023, together with cash flows from operations, will provide liquidity sufficient to meet our cash needs and fund our operations and planned capital expenditures for at least the next 12 months.
We believe that our existing cash and cash equivalents and available for sale investments, which totaled $516.5 million as of December 31, 2024, together with cash flows from operations, will provide liquidity sufficient to meet our cash needs and fund our operations and planned capital expenditures for at least the next 12 months.
The number of shares earned at the end of the three-year periods will vary based on actual performance, from 0% to 200% of the number of PSUs granted. If the performance goals are not met, no shares will be earned.
The number of shares earned at the end of the three-year periods will vary based on actual performance, from 0% to 200% of the number of PSUs 85 Table of Contents granted. If the performance goals are not met, no shares will be earned.
We expense prelaunch inventory as research and development expense in the period incurred unless objective and persuasive evidence exists that regulatory approval and subsequent commercialization of a product candidate is probable and we also expect future economic benefit from the sales of the product candidate to be realized.
We expense prelaunch inventory as R&D expense in the period incurred unless objective and persuasive evidence exists that regulatory approval and subsequent commercialization of a product candidate is probable, and we also expect future economic benefit from the sales of the product candidate to be realized.
We have experienced and continue to experience supply disruptions that began during the COVID-19 pandemic, but to date we have managed to avoid major delays in implant procedures due to those issues.
We have experienced supply disruptions that began during the COVID-19 pandemic, but to date we have managed to avoid major delays in implant procedures due to those issues.
We expect research and development expenses as a percentage of revenue to vary over time depending on the level and timing of initiating new product development efforts and new clinical development activities.
We expect R&D expenses as a percentage of revenue to vary over time depending on the level and timing of initiating new product development efforts and new clinical development activities.
Our gross margin may increase slightly to the extent our production volumes increase and we receive discounts on the costs charged by our contract manufacturers, thereby reducing our per unit costs, and when we 82 Table of Contents implement price increases on our products, thereby increasing our revenue.
Our gross margin may increase slightly to the extent our production volumes increase and we receive discounts on the costs charged by our contract manufacturers, thereby reducing our per unit costs, and when we implement price increases on our products, thereby increasing our revenue.
The primary purpose of this program is to assist patients with making a connection with a qualified healthcare provider based on their specific needs. In 2022, we initiated a digital scheduling pilot program to facilitate and streamline patient access to care. We plan to continue to enhance this scheduling capability during 2024.
The primary purpose of this program is to assist patients with making a connection with a qualified healthcare provider based on their specific needs. In 2022, we initiated a digital scheduling program to facilitate and streamline patient access to care. We intend to continue to enhance this scheduling capability during 2025.
The primary driver of this change was an increase of $75.7 million in compensation, including salaries, commissions, stock-based compensation, and other employee-related expenses, mainly as a result of increased headcount.
The primary driver of this change was an increase of $66.6 million in compensation, including salaries, commissions, stock-based compensation, and other employee-related expenses, mainly as a result of increased headcount.
The overhead costs include the cost of material procurement, depreciation expense for production equipment, and operations supervision and management personnel, including employee compensation, stock-based compensation, supplies, and travel. We expect cost of goods sold to increase or decrease in absolute dollars primarily as, and to the extent, our revenue grows or declines, respectively.
The overhead costs include the cost of material procurement, depreciation expense for manufacturing equipment, amortization of internal-use software, and operations and quality supervision and management personnel, including employee compensation, stock-based compensation, supplies, and travel. We expect cost of goods sold to increase or decrease in absolute dollars primarily as, and to the extent, our revenue grows or declines, respectively.
We anticipate further capital expenditures in 2024, primarily for additional production equipment and our SleepSync™ platform, computer hardware and software, and leasehold improvements on our corporate office buildings.
We anticipate further capital expenditures in 2025, primarily for additional manufacturing equipment and our SleepSync™ platform, computer hardware and software, and leasehold improvements on our corporate office buildings.
Our Inspire system is currently reimbursed primarily on a per-patient prior authorization basis for patients covered by commercial payors, under Local Coverage Determinations for patients covered by Medicare, and under U.S. government contract for patients who are treated by the Veterans Health Administration.
Our Inspire system is currently covered on a per-patient basis for patients insured by commercial payors, under Local Coverage Determinations for patients insured by Medicare and Medicare Advantage, and under U.S. government contract for patients who are treated by the Veterans Health Administration.
Also in June 2023, we received approval from the FDA on an expanded indication which includes an increase on the upper limit of the Apnea Hypopnea Index to 100 events per hour from 65, and raises the Body Mass Index ("BMI") warning in the labeling to 40 from 32, and we also received FDA approval of our new physician programmer, called the SleepSync™ programmer, which we expect to formally launch in the U.S. in early 2024.
In June 76 Table of Contents 2023, we received approval from the FDA on an expanded indication which includes an increase on the upper limit of the Apnea Hypopnea Index to 100 events per hour from 65 and raises the Body Mass Index ("BMI") warning in the labeling to 40 from 32, and we also received FDA approval of our new physician programmer, called the SleepSync™ programmer, which we launched in the U.S. in late 2024.
In 2023, our R&D and SG&A expenditures increased significantly over the prior year levels, and we anticipate further increases during 2024. Our SG&A expenditures, primarily for increasing headcount and advertising, may 86 Table of Contents exceed any associated increases in revenues, and therefore would reduce our cash flow from operations.
In 2024, our SG&A expenditures increased significantly over the prior year levels, and we anticipate further increases during 2025. Our SG&A expenditures, primarily for increasing headcount and advertising, may exceed any associated increases in revenues, and therefore would reduce our cash flow from operations.
As of February 9, 2024, we have secured positive coverage policies with many U.S. commercial payors, including virtually all large national commercial insurers, covering approximately 260 million lives in the U.S. In addition, all seven Medicare Administrative Contractors published final policies in 2020 that provide coverage of Inspire therapy when certain coverage criteria are met.
As of February 10, 2025, we have secured positive coverage policies with many U.S. commercial payors, including all large national commercial insurers, covering approximately 260 million lives in the U.S. In addition, all seven Medicare Administrative Contractors provide coverage of Inspire therapy when certain coverage criteria are met.
Components of Our Results of Operations Revenue We derive primarily all of our revenue from the sale of our Inspire system to hospitals and ASCs in the U.S., select countries in Europe, Japan, Singapore, and Hong Kong.
Components of Our Results of Operations Revenue We derive primarily all of our revenue from the sale of our Inspire system to hospitals and ASCs in the U.S. and in select countries in Europe and the Asia Pacific region.
We also anticipate R&D expenses will continue to be significant in 2024, primarily related to the ongoing development of the SleepSync™ platform and next generation products.
We also anticipate R&D expenses will increase in 2025, primarily related to the ongoing development of the SleepSync™ platform and next generation products.
Our long-term cash requirements also will be significantly impacted by the level of our investment in commercialization, entry and expansion into new markets such as Hong Kong and Australia, whether we make strategic acquisitions, and competition. We cannot accurately predict our long-term cash requirements at this time.
Our long-term cash requirements also will be significantly impacted by the level of our investment in commercialization, entry and expansion into new markets, whether we make strategic acquisitions, whether we repurchase more shares of our common stock, and competition. We cannot accurately predict our long-term cash requirements at this time.
At December 31, 2023, we had $146.2 million in money market funds, $243.6 million in U.S. government securities, and $40.4 million in corporate debt securities, certificates of deposit, commercial paper, and asset-asset-backed securities. See Note 2 to our audited financial statements for additional information on our investments.
At December 31, 2024, we had $59.6 million in money market funds, $267.4 million in U.S. Treasury debt securities, and $99.0 million in corporate debt securities, commercial paper, certificates of deposit, and asset-asset-backed securities. See Note 2 to our audited financial statements for additional information on our investments.
During the third quarter of 2023, we also began experiencing an inventory supply issue related to our polyurethane-based stimulation leads, one component of the Inspire system currently used only in the European market.
During the third quarter of 2023, we experienced an inventory supply issue related to our polyurethane-based stimulation leads, one component of the Inspire system used only in the European market at that time.
Investing Activities Net cash used in investing activities for 2023 was $294.8 million and consisted primarily of the purchase of investments of $281.2 million, partially offset by $10.2 million of proceeds from sales or maturities of investments.
We also purchased strategic investments of $0.3 million. 84 Table of Contents Net cash used in investing activities for 2023 was $294.8 million and consisted primarily of the purchase of investments of $281.2 million, partially offset by $10.2 million of proceeds from sales or maturities of investments.
For the year ended December 31, 2023, we generated revenue of $624.8 million with a gross margin of 84.5% and a net loss of $21.2 million, compared to revenue of $407.9 million with a gross margin of 83.8% and a net loss of $44.9 million for the year ended December 31, 2022, and revenue of $233.4 million with a gross margin of 85.7% and a net loss of $42.0 million for the year ended December 31, 2021.
For the year ended December 31, 2024, we generated revenue of $802.8 million with a gross margin of 84.7% and net income of $53.5 million, compared to revenue of $624.8 million with a gross margin of 84.5% and a net loss of $21.2 million for the year ended December 31, 2023, and revenue of $407.9 million with a gross margin of 83.8% and a net loss of $44.9 million for the year ended December 31, 2022.
If 200% of the PSUs outstanding as of December 31, 2023 are ultimately earned, the total stock-based compensation expense recognized over the three-year period ending December 31, 2024 will be $83.9 million.
If 200% of the PSUs outstanding as of December 31, 2024 are ultimately earned, the total stock-based compensation expense recognized over the five-year period ending December 31, 2026 will be $142.8 million.
On the other hand, our gross margin may decrease slightly to the extent our yields decrease, or materials and labor prices increase due to supply chain issues and inflation, thereby increasing our per unit costs. However, our gross margin may also fluctuate from quarter to quarter due to seasonality and foreign currency exchange rates.
On the other hand, our gross margin may decrease slightly to the extent our yields decrease, or materials and labor prices increase due to supply chain issues and inflation, thereby increasing our per unit costs.
Our business has grown rapidly in recent years, resulting in substantially increased revenues, and we expect that our business will continue to grow. However, our revenue growth rate has generally declined in recent periods, and it may continue to do so as a result of the difficulty of maintaining growth rates as our revenues increase to higher levels.
However, our revenue growth rate has generally declined in recent periods, and it may continue to do so as a result of the difficulty of maintaining growth rates as our revenues increase to higher levels.
We spent $23.6 million on purchases of property and equipment in 2023, mainly on testing systems and production equipment for our next generation Inspire system, our SleepSync™ platform, computer hardware and software, and leasehold improvements.
We spent $39.1 million on purchases of property and equipment in 2024, mainly on testing systems and manufacturing equipment for our next generation Inspire system, our SleepSync™ platform, computer hardware 82 Table of Contents and software, and leasehold improvements.
Revenue growth was primarily due to increased market penetration in existing territories, the expansion of our European sales representatives into new territories, 84 Table of Contents increased sales in the Asia Pacific region, and, we believe, increased physician and patient awareness of our Inspire system.
Revenue growth in the U.S. was primarily due to increased market penetration in existing centers, the expansion into new territories and centers, and, we believe, increased physician and patient awareness of our Inspire system.
Research and Development Expenses Research and development expenses consist primarily of product development, engineering, clinical studies to develop and support our products, regulatory expenses, quality assurance, testing, consulting services, prelaunch inventory, and other costs associated with the next generation versions of the Inspire system and SleepSync™, a cloud-based patient management system.
However, our gross margin may also fluctuate from quarter to quarter due to seasonality and foreign currency exchange rates. 78 Table of Contents Research and Development Expenses Research and development ("R&D") expenses consist primarily of product development, engineering, clinical studies to develop and support our products, regulatory expenses, quality assurance, testing, consulting services, prelaunch inventory, and other costs associated with the next generation versions of the Inspire system and SleepSync™, a cloud-based patient management system.
In 2022, the FDA approved our silicone-based stimulation and sensing leads in the U.S., which replaced the polyurethane versions of the leads, and we stopped manufacturing polyurethane leads. We applied for European Union ("EU") Medical Devices Regulation ("MDR") approval in December 2021, which we expect to obtain in the second quarter of 2024, following delays in the process.
In 2022, the FDA approved our silicone-based stimulation and sensing leads in the U.S., which replaced the polyurethane versions of the leads, and we stopped manufacturing polyurethane leads. We applied for EU MDR certification in December 2021, which we received in July 2024, following industry-wide delays in the process.
Revenue generated outside of the U.S. was $18.6 million in the year ended December 31, 2023, an increase of $5.6 million, or 43.0%, over the year ended December 31, 2022.
Revenue generated outside of the U.S. was $31.8 million in the year ended December 31, 2024, an increase of $13.1 million, or 70.6%, over the year ended December 31, 2023.
No single customer accounted for more than 10% of our revenue. We rely on third-party suppliers to manufacture our Inspire system and its components. Many of these suppliers are currently single source suppliers.
For the year ended December 31, 2024, 96.0% of our revenue was derived in the U.S. and 4.0% was derived outside of the U.S. No single customer accounted for more than 10% of our revenue. We rely on third-party suppliers to manufacture our Inspire system and its components. Many of these suppliers are currently single source suppliers.
The 2024 Medicare national average ASC reimbursement is $24,847, a decrease of 1% from the 2023 rate. The 2024 Medicare national average physician reimbursement is $823 for implantation of a hypoglossal nerve stimulator, a 6% decrease over the 2023 payment. The reimbursement for the DISE procedure in the hospital setting is $1,617, an 803% increase over the prior year amount.
The 2025 Medicare national average physician reimbursement is $816 for implantation of a hypoglossal nerve stimulator, a 1% decrease over the 2024 payment. The reimbursement for the DISE procedure in the hospital setting is $1,724, a 7% increase over the prior year amount.
Revenue information by region is summarized as follows: Year Ended December 31, 2023 2022 Change Amount % of Revenue Amount % of Revenue $ % (in thousands, except percentages) United States $ 606,178 97.0 % $ 394,833 96.8 % $ 211,345 53.5 % All other countries 18,621 3.0 % 13,023 3.2 % 5,598 43.0 % Total revenue $ 624,799 100.0 % $ 407,856 100.0 % $ 216,943 53.2 % Revenue generated in the U.S. was $606.2 million for the year ended December 31, 2023, an increase of $211.3 million, or 53.5%, over the year ended December 31, 2022.
Revenue information by region is summarized as follows: Year Ended December 31, 2024 2023 Change Amount % of Revenue Amount % of Revenue $ % (in thousands, except percentages) United States $ 771,040 96.0 % $ 606,178 97.0 % $ 164,862 27.2 % All other countries 31,764 4.0 % 18,621 3.0 % 13,143 70.6 % Total revenue $ 802,804 100.0 % $ 624,799 100.0 % $ 178,005 28.5 % Revenue generated in the U.S. was $771.0 million for the year ended December 31, 2024, an increase of $164.9 million, or 27.2%, over the year ended December 31, 2023.
As of December 31, 2023 ($ in thousands) Total Fiscal 2024 After Fiscal 2024 Recorded contractual obligations: Operating leases (1) $ 35,089 $ (3,582) $ 38,671 Unrecorded contractual obligations: Purchase obligations (2) 91,375 91,375 — Total $ 126,464 $ 87,793 $ 38,671 (1) See Note 3 to our audited consolidated financial statements. (2) Primarily purchase obligations to suppliers for inventory.
As of December 31, 2024 ($ in thousands) Total Fiscal 2025 After Fiscal 2025 Recorded contractual obligations: Operating leases (1) $ 41,330 $ 3,204 $ 38,126 Unrecorded contractual obligations: Purchase obligations (2) 85,968 85,968 — Total $ 127,298 $ 89,172 $ 38,126 (1) See Note 3 to our audited consolidated financial statements. (2) Primarily purchase obligations to suppliers for inventory.
In the interim, we received derogation approval from the Dutch, German, Swiss, and Belgian national competent authorities allowing us to place the silicone-based leads on the market in those countries until various dates in 2024 or until we receive certification under the EU MDR, whichever occurs first.
In the interim, we had received a derogation pursuant to Article 59 of the EU MDR from the Dutch, German, Swiss, Belgian, and Austrian competent authorities, and the British equivalent, i.e. exceptional use authorization, from the United Kingdom national competent authority, allowing us to continue to place the silicone-based leads on the market in those countries until various dates in 2024 or until we received certification under the EU MDR, whichever occurred first.
"Item 1A. Risk Factors’’ and elsewhere in this Annual Report on Form 10-K. Overview We are a medical technology company focused on the development and commercialization of innovative, minimally invasive solutions for patients with OSA. Our proprietary Inspire system is the first and only FDA-approved neurostimulation technology that provides a safe and effective treatment for moderate to severe OSA.
"Item 1A. Risk Factors’’ and elsewhere in this Annual Report on Form 10-K. Overview We are a medical technology company focused on the development and commercialization of innovative, minimally invasive solutions for patients with obstructive sleep apnea ("OSA").
Selling, General and Administrative Expenses SG&A expenses increased $131.3 million, or 40.9%, to $452.0 million for the year ended December 31, 2023 compared to $320.7 million for the year ended December 31, 2022.
Selling, General and Administrative Expenses SG&A expenses increased $77.6 million, or 17.2%, to $529.6 million for the year ended December 31, 2024 compared to $452.0 million for the year ended December 31, 2023.
Net cash provided by operating activities was $11.6 million for 2022 and consisted of a net loss of $44.9 million, non-cash charges of $54.6 million, and a decrease in net operating assets of $1.8 million.
Net cash provided by operating activities was $24.7 million for 2023 and consisted of a net loss of $21.2 million, non-cash charges of $86.6 million, and a decrease in net operating assets of $40.8 million.
We also continue to make significant investments to build our sales and marketing organization by increasing the number of U.S. and European sales representatives and continuing our direct-to-consumer marketing efforts in existing and new markets throughout the U.S. and in Europe.
We also continue to make significant investments to build our sales and marketing organization by increasing the number of U.S., European, and Japanese sales representatives and continuing our direct-to-consumer marketing efforts in existing and new markets. During 2024, we activated 285 U.S. centers bringing the total to 1,435 U.S. medical centers implanting Inspire therapy as of December 31, 2024.
This change was primarily due to an increase of $21.7 million of compensation and employee-related expenses, mainly as a result of increased headcount and stock-based compensation expense and $20.8 million of incremental ongoing research and development costs, including ongoing development of the SleepSync™ platform and the next generation Inspire neurostimulator and physician programmer.
This change was primarily due to a decrease of $23.6 million in ongoing research and development costs, primarily with respect to our next generation versions of the Inspire neurostimulator and our SleepSync™ platform, partially offset by an increase of $20.1 million in compensation and employee-related expenses, mainly as a result of increased headcount and stock-based compensation expense, and an increase of $1.1 million in regulatory and clinical studies expenses and quality compliance fees.
Net cash used in investing activities for 2022 was $19.6 million and consisted of the purchase of strategic investments of $10.5 million and the purchases of property and equipment, net of $9.1 million, mainly for testing systems, production equipment, and leasehold improvements on our corporate office. 88 Table of Contents Financing Activities Net cash provided by financing activities was $14.0 million for 2023 and consisted primarily of proceeds from the exercise of stock options of $25.8 million and proceeds from the issuance of common stock from our employee stock purchase plan of $5.3 million, partially offset by $17.2 million of taxes paid on net share settlement of equity awards.
Net cash provided by financing activities was $14.0 million for 2023 and consisted primarily of proceeds from the exercise of stock options of $25.8 million and proceeds from the issuance of common stock from our ESPP of $5.3 million, partially offset by $17.2 million of taxes paid on net share settlement of equity awards.
Our accumulated deficit as of December 31, 2023 was $345.4 million. 80 Table of Contents We have invested heavily in product development. Our research and development activities have been centered on driving continuous improvements to our Inspire therapy.
Our accumulated deficit as of December 31, 2024 was $291.9 million. We have invested heavily in product development. Our research and development activities have been centered on driving continuous improvements to our Inspire therapy. We have also made significant investments in clinical studies to demonstrate the safety and efficacy of our Inspire therapy and to support regulatory submissions.
A Category I code (42975) is also used for Drug-Induced Sleep Endoscopy ("DISE") to evaluate sleep disordered breathing, which may be a necessary procedure to determine which patients are appropriate for Inspire therapy. The Medicare national average 2024 payment to implant our device in a hospital outpatient site of service is $29,586, an increase of 1% from the 2023 rate.
A Category I code (42975) is also used for Drug-Induced Sleep Endoscopy ("DISE") to evaluate sleep disordered breathing, which may be a necessary procedure to determine which patients are appropriate for Inspire therapy. In November 2024, the final 2025 Medicare reimbursement payments were announced.
Additionally, patients with a higher BMI are subject to a larger neck circumference and present predominantly with lateral-wall collapse. A combination of tongue-based collapse and lateral-wall collapse is identified as a complete concentric collapse of the upper airway. Inspire is contraindicated for complete concentric collapse.
A combination of tongue base collapse and lateral wall collapse is identified as a complete concentric collapse of the upper airway. Inspire is contraindicated for complete concentric collapse.
Research and Development Expenses Research and development expenses increased $47.9 million, or 69.8%, to $116.5 million for the year ended December 31, 2023 compared to $68.6 million for the year ended December 31, 2022.
Research and Development Expenses Research and development expenses decreased $2.4 million, or 2.1%, to $114.1 million for the year ended December 31, 2024 compared to $116.5 million for the year ended December 31, 2023.
Reimbursement in other countries can often be established through a combination of private (commercial insurance) and public funding sources, or at the hospital level through innovation budgets. The procedures performed to implant, revise, or explant our device are described for billing purposes in the U.S. with Category I Current Procedural Terminology (“CPT”) codes (64582, 64583, and 64584, respectively).
The procedures performed to implant, revise, or explant our Inspire IV device are described for billing purposes in the U.S. with Category I Current Procedural Terminology codes (64582, 64583, and 64584, respectively).
Other (Income) Expense, Net Other (income) expense, net changed by $17.1 million, or 512.7%, to $20.4 million of income for the year ended December 31, 2023 compared to $3.3 million of income for the year ended December 31, 2022.
Other Income, Net Other income, net increased by $2.0 million, or 9.8%, to $22.4 million of income for the year ended December 31, 2024 compared to $20.4 million of income for the year ended December 31, 2023.
We expect GLP-1s may help patients address their lateral wall collapse, making them a potential candidate for Inspire therapy to the extent they also have tongue-based collapse.
While weight loss may help reduce a patient’s AHI and other OSA symptoms, numerous other studies have shown that weight loss alone will not resolve OSA for the vast majority of patients. We expect GLP-1s may help patients address their lateral wall collapse, making them a potential candidate for Inspire therapy to the extent they also have tongue base collapse.
The number of PSUs that will ultimately be earned is based on our performance relative to pre-established goals for the three-year periods ending December 31, 2024 and 2025, respectively. Management expectations related to the achievement of the performance goals associated with PSU grants is assessed each reporting period, which determines the amount of stock-based compensation expense recorded during the period.
Management expectations related to the achievement of the performance goals associated with PSU grants is assessed each reporting period, which determines the amount of stock-based compensation expense recorded during the period.
If the performance conditions are not met or not expected to be 89 Table of Contents met, any compensation expense previously recognized associated with the grant will be reversed which will impact our operating results.
If the performance conditions are not met or not expected to be met, any compensation expense previously recognized associated with the grant will be reversed which will impact our operating results. Recent Accounting Pronouncements A discussion of recent accounting pronouncements is included in Note 2 to our financial statements contained in this Annual Report on Form 10-K.
We plan to continue to refine our approach to direct-to-consumer outreach, including increasing attention to digital advertising directed towards qualified patients. We expect to maintain our level of direct-to-consumer activities. We have a call center which we refer to as the Inspire Advisor Care Program ("ACP").
Moving forward, we plan to refine and optimize our outreach strategies, with an emphasis on expanding digital advertising efforts to reach more qualified patients. We generally expect to maintain our level of direct-to-consumer expenditures. We have a call center which we refer to as the Inspire Advisor Care Program.
We estimate the impact on our revenue during the fourth quarter of 2023 was approximately $4 million.
We estimate the impact during the fourth quarter of 2023 was approximately $4.0 million in lost revenue opportunity, most of which we believe was recovered during the first half of 2024.
Our customers are reimbursed the cost required to treat each patient through various third-party payors, such as commercial payors and government agencies.
Our customers are reimbursed according to the coding and correlated payment by various third-party payors, such as commercial payors and government healthcare programs.
Our inventory on-hand has been constrained by the continuing supply chain challenges and component shortages, although the supply chain constraints eased somewhat throughout 2023.
Our inventory on-hand has been constrained by the supply chain challenges and component shortages, although to a lesser degree in 2024 than in prior periods.
Overall revenue growth was primarily due to increased market penetration in existing territories, expansion into new territories, and, we believe, increased physician and patient awareness of our Inspire system, and to a lesser extent, a list price increase that began to impact some customers in May 2022, partially offset by ENT surgeon capacity constraints and reduced procedures as a result of the polyurethane-based lead shortage in Europe and the factors described under "Components of our Results of Operations - Revenue" above.
Overall revenue growth was primarily due to increased market penetration in existing centers, expansion into new territories and centers, and, we believe, increased physician and patient awareness of our Inspire system, partially offset by ENT surgeon capacity constraints.
Year Ended December 31, 2022 Compared to Year Ended December 31, 2021 For a discussion of our results of operations for the year ended December 31, 2022, including a year-to-year comparison between 2022 and 2021, refer to Part II, Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations" in our Annual Report on Form 10-K for the year ended December 31, 2022.
Year Ended December 31, 2023 Compared to Year Ended December 31, 2022 For a discussion of our results of operations for the year ended December 31, 2023, including a year-to-year comparison between 2023 and 2022, refer to Part II, Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations" in our Annual Report on Form 10-K for the year ended December 31, 2023. 81 Table of Contents Liquidity and Capital Resources We believe our balance sheet and liquidity as of February 10, 2025 provides us with flexibility, and that our cash, cash equivalents, and investments will satisfy our operating needs and capital expenditures for at least the next 12 months.
The objective of this outreach is to bring patients to our website, where they can find educational materials and videos on sleep apnea and the use and benefits of our Inspire therapy, contact information for physicians and clinical sites, and information regarding community awareness events. Further, our team leverages the Inspire Sleep app for patient education.
On our website, patients can explore educational materials and videos about sleep apnea, learn about the benefits of Inspire therapy, find physician and clinical site contact information, and stay informed about community awareness events. We also use the Inspire Sleep app as a valuable tool for patient education.
Other (Income) Expense, Net Other (income) expense consists primarily of interest and dividend income, interest expense under our former credit facility, the impacts of foreign currency transactions and remeasurements, and gains and losses on investments. 83 Table of Contents Results of Operations Year Ended December 31, 2023 Compared to Year Ended December 31, 2022 Year Ended December 31, Change 2023 2022 $ % (in thousands, except percentages) Revenue $ 624,799 $ 407,856 $ 216,943 53.2 % Cost of goods sold 96,576 66,115 30,461 46.1 % Gross profit 528,223 341,741 186,482 54.6 % Gross margin 84.5 % 83.8 % Operating expenses: Research and development 116,536 68,645 47,891 69.8 % Selling, general and administrative 451,958 320,688 131,270 40.9 % Total operating expenses 568,494 389,333 179,161 46.0 % Operating loss (40,271) (47,592) 7,321 (15.4) % Other income, net (20,365) (3,324) (17,041) 512.7 % Loss before income taxes (19,906) (44,268) 24,362 (55.0) % Income taxes 1,247 613 634 103.4 % Net loss $ (21,153) $ (44,881) $ 23,728 (52.9) % Revenue Revenue increased $216.9 million, or 53.2%, to $624.8 million for the year ended December 31, 2023 compared to the year ended December 31, 2022.
Other Income, Net Other income, net consists primarily of interest and dividend income, interest expense under our former credit facility, the impacts of foreign currency transactions and remeasurements, and gains and losses on investments. 79 Table of Contents Results of Operations Year Ended December 31, 2024 Compared to Year Ended December 31, 2023 Year Ended December 31, Change 2024 2023 $ % (in thousands, except percentages) Revenue $ 802,804 $ 624,799 $ 178,005 28.5 % Cost of goods sold 122,986 96,576 26,410 27.3 % Gross profit 679,818 528,223 151,595 28.7 % Gross margin 84.7 % 84.5 % Operating expenses: Research and development 114,128 116,536 (2,408) (2.1) % Selling, general and administrative 529,607 451,958 77,649 17.2 % Total operating expenses 643,735 568,494 75,241 13.2 % Operating income (loss) 36,083 (40,271) 76,354 (189.6) % Other income, net (22,370) (20,365) (2,005) 9.8 % Income (loss) before income taxes 58,453 (19,906) 78,359 (393.6) % Income taxes 4,944 1,247 3,697 296.5 % Net income (loss) $ 53,509 $ (21,153) $ 74,662 (353.0) % Revenue Revenue increased $178.0 million, or 28.5%, to $802.8 million for the year ended December 31, 2024 compared to the year ended December 31, 2023.
This change was due to an increase of $15.5 million in interest and dividend income due to higher interest rates on our higher cash, cash equivalents, and investment balances, and a decrease of $1.7 million in interest expense due to the early termination of our credit facility, partially offset by a $0.1 million change in foreign currency translation and remeasurement gains due to exchange rates. 85 Table of Contents Income Taxes We recorded a provision for income taxes of $1.2 million and $0.6 million for the years ended December 31, 2023 and 2022, respectively.
This change was primarily due to an increase of $2.7 million in interest and dividend income due to higher cash, cash equivalents, and investment balances, partially offset by an increase in net losses of $0.7 million in foreign currency translation and remeasurement gains due to exchange rates.
Stock-Based Compensation We maintain an equity incentive plan to provide lon g-term incentives for eligible employees, consultants, and members of the board of directors. The plan allows for the issuance of performance stock units ("PSUs"), and d uring 2022 and 2023, we granted PSUs to officers and key employees.
The reserve for excess and obsolete inventory was $1.0 million and $2.4 million as of December 31, 2024 and 2023, respectively. Stock-Based Compensation We maintain an equity incentive plan to provide lon g-term incentives for eligible employees, consultants, and members of the board of directors.
Net cash provided by financing activities was $235.1 million for 2022 and consisted primarily of proceeds from the offering of common stock of $243.8 million, as well as proceeds from the exercise of stock options of $12.1 million, and proceeds from the issuance of common stock from our employee stock purchase plan of $3.7 million, partially offset by $24.5 million in payments on our long-term debt obligation, which we prepaid in August 2022, and less than $0.1 million of taxes paid on net share settlement of equity awards.
Financing Activities Net cash used in financing activities was $52.4 million for 2024 and consisted primarily of a $75.0 million payment for our ASR agreement and $5.2 million of taxes paid on net share settlement of equity awards, partially offset by proceeds from the exercise of stock options of $22.2 million and proceeds from the issuance of common stock from our Employee Stock Purchase Plan ("ESPP") of $5.6 million.
These results reflect an increase in sales of our Inspire system of $211.3 million in the U.S. and an increase of $5.6 million outside of the U.S.
The increase was attributable to a $164.9 million increase in sales of our Inspire system in the U.S and an increase of $13.1 million outside of the U.S.
Gross margin was 84.5% for the year ended December 31, 2023 compared to 83.8% for the year ended December 31, 2022.
Gross margin was 84.7% for the year ended December 31, 2024 compared to 84.5% for the year ended December 31, 2023. This increase was primarily due to increased sales volume and manufacturing efficiencies.
The increase in working capital was primarily due to the following factors: • an increase of $9.0 million in cash and cash equivalents and short-term available for sale investments due primarily to sales of the Inspire system, proceeds from the exercise of stock options, and interest and dividend income; • an increase of $28.7 million in accounts receivable due to higher sales which occurred during the fourth quarter of 2023; • an increase of $22.0 million in inventory balances which increased as supply chain issues ease; and • an increase of $4.1 million in prepaid expense and other current assets which increased primarily due to miscellaneous prepaid expenses and interest income receivable.
The increase in working capital was primarily due to the following factors: • an increase of $46.2 million in inventory balances which increased as supply chain issues eased and we increased inventory levels to support higher sales and the anticipated 2025 launch of our next generation Inspire system in the U.S.; • an increase of $3.2 million in accounts receivable due to higher sales which occurred during the fourth quarter of 2024; • an increase of $2.5 million in prepaid expense and other current assets which increased primarily due to increases in miscellaneous receivables and interest income receivable; and • a decrease of $0.2 million in accounts payable.
Therefore, we do not believe there is not a significant overlap between the Inspire patient population and the patient population being treated with GLP-1s today. While we cannot quantify the impact, we believe that there could be a benefit to our business as a result of GLP-1s, although there can be no assurance of such benefit.
Therefore, we believe there is not a notable overlap between the Inspire patient population and the patient population being treated with GLP-1s today.
Likewise, the timing of FDA approval of a next generation product, if granted, could have a significant impact on the carrying value of the inventory of our previous generation product, and therefore our reported operating results. During 2022, we recorded a $1.8 million inventory reserve related to product introductions, including the new silicone leads and the Bluetooth®-enabled patient remote.
Likewise, the timing of FDA approval of a next generation product, if granted, and the associated commercial launch, could have a significant impact on the carrying value of the inventory of our previous generation product, and therefore our reported operating results. The net inventory balance was $80.1 million and $33.9 million as of December 31, 2024 and 2023, respectively.
Reimbursement in other countries can often be established through a combination of private (commercial insurance) and public funding sources, or at the hospital level through innovation budgets. For the year ended December 31, 2023, 97.0% of our revenue was derived in the U.S. and 3.0% was derived outside of the U.S.
The 2025 Medicare national average physician reimbursement for the DISE procedure is $94, a 2% decrease over the prior year amount. 75 Table of Contents Reimbursement in other countries can often be established through a combination of private (commercial insurance) and public funding sources, or at the hospital level through innovation budgets.
For example, we have historically experienced seasonality in our first and fourth quarters and have experienced adverse impacts on our revenue due to the COVID-19 pandemic and foreign currency exchange rates.
For example, we have historically experienced seasonality in our first and fourth quarters. We have also previously experienced adverse impacts on our revenue due to the prior delay in obtaining EU MDR approval of our silicone-based leads and foreign currency exchange rates. In addition, we believe our revenue growth has been adversely impacted by lack of ENT surgeon capacity.
In the ASC setting, the reimbursement for the DISE procedure is $757, a 714% increase from the 2023 79 Table of Contents amount. The 2024 Medicare national average physician reimbursement for the DISE procedure is $95, a 2% decrease over the prior year amount.
In the ASC setting, the reimbursement for the DISE procedure is $792, a 714% increase from the 2024 amount.
The non-cash charges consisted primarily of stock-based compensation, which increased mainly as a result of granting more stock options and restricted stock units to more employees at a higher fair market value, as well as the introduction of performance stock unit grants.
The non-cash charges consisted primarily of stock-based compensation, which increased mainly as a result of granting more equity awards to a greater number of employees as compared to the same prior year period.