14.   Fair Value Measurements.

Assets (Liabilities) Measured at Fair Value on a Recurring Basis

Our financial assets and (liabilities) carried at fair value and measured on a recurring basis as of June 30, 2025 and December 31, 2024 consisted of the following (in thousands):

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Certain of our past business combinations involve the potential for the payment of future contingent consideration, generally based on a percentage of future product sales or upon attaining specified future revenue or other milestones. The contingent consideration liability is re-measured at the estimated fair value at the end of each reporting period with the change in fair value recognized within operating expenses in the accompanying consolidated statements of income for such period. We measure the initial liability and re-measure the liability on a recurring basis using Level 3 inputs as defined under authoritative guidance for fair value measurements. Changes in the fair value of our contingent consideration liabilities during the three and six-month periods ended June 30, 2025 and 2024 consisted of the following (in thousands):

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As of June 30, 2025, $1.7 million in contingent consideration liability was included in other long-term obligations and $0.3 million in contingent consideration liability was included in accrued expenses in our consolidated balance sheet. As of December 31, 2024, $3.1 million in contingent consideration liability was included in other long-term obligations and $0.4 million in contingent consideration liability was included in accrued expenses in our consolidated balance sheet.

Payments related to the settlement of the contingent consideration liability recognized at fair value as of the applicable acquisition date of $2.5 million and $0.1 million for the six-month periods ended June 30, 2025 and 2024, respectively, have been reflected as a cash outflow from financing activities in the accompanying consolidated statements of cash flows. Payments related to increases in the contingent consideration liability subsequent to the date of acquisition of $0.1 million and $0.1 million for the six-month periods ended June 30, 2025 and 2024, respectively, are reflected as operating cash flows.

The recurring Level 3 measurement of our contingent consideration liabilities included the following significant unobservable inputs at June 30, 2025 and December 31, 2024 (amounts in thousands):

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The contingent consideration liability is re-measured to fair value each reporting period. Significant increases or decreases in projected revenues, based on our most recent internal operational budgets and long-range strategic plans, discount rates or the time until payment is made would have resulted in a significantly lower or higher fair value measurement. Our determination of the fair value of the contingent consideration liability could change in future periods based upon our ongoing evaluation of these significant unobservable inputs. We intend to record any such change in the fair value of contingent consideration liability to operating expenses in our consolidated statements of income.

Fair Value of Other Assets (Liabilities)

The carrying amount of cash and cash equivalents, receivables, and trade payables approximate fair value because of the immediate, short-term maturity of these financial instruments. The fair value of our long-term debt under our Convertible Notes was $934.4 million as of June 30, 2025 and was determined based on quoted prices in markets that are not active, which is considered a Level 2 valuation input. The fair value of assets and liabilities whose carrying value approximates fair value is determined using Level 2 inputs, with the exception of cash and cash equivalents, which use Level 1 inputs.

We recognize or disclose the fair value of certain assets, such as non-financial assets, primarily property and equipment, right-of-use operating lease assets, equity investments, intangible assets and goodwill in connection with impairment evaluations. Such assets are reported at carrying value and are not subject to recurring fair value measurements. We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Fair value is generally determined based on discounted future cash flow. All our nonrecurring valuations use significant unobservable inputs and therefore fall under Level 3 of the fair value hierarchy.

Our equity investments in privately-held companies were $25.9 million and $22.8 million at June 30, 2025 and December 31, 2024, respectively, which are included within other long-term assets in our consolidated balance sheets. We analyze our investments in privately-held companies to determine if they should be accounted for using the equity method based on our ability to exercise significant influence over operating and financial policies of the investment whereby we record our proportionate share of the investee’s earnings or losses; amortization of differences between our investment basis and underlying equity in net assets of the investee, excluding the component representing goodwill; and impairment, if any, as a component of other income (expense) — net for each reporting period. Investments not accounted for under the equity method of accounting are accounted for at cost minus impairment, if applicable, plus or minus changes in valuation resulting from observable transactions for identical or similar investments. For the six-month periods ended June 30, 2025 and 2024, we recorded no impairment charges related to our equity investments.

Current Expected Credit Losses

Our outstanding long-term notes receivable, including accrued interest and an allowance for current expected credit losses, were $21.0 million and $9.4 million as of June 30, 2025 and December 31, 2024, respectively. Long-term notes receivable increased $11.6 million for the six-month period ended June 30, 2025 related to loans issued to FluidX Medical Technology, Inc. and Protaryx Medical Inc. As of June 30, 2025 and December 31, 2024, we had an allowance for current expected credit losses of $2.4 million and $1.4 million, respectively, associated with these notes receivable. We assess the allowance for current expected credit losses on an individual security basis, due to the limited number of securities, using a probability of default model, which is based on relevant information about past events, including historical experience, current conditions and reasonable and supportable forecasts that affect the expected collectability of securities, and other security specific factors.

The table below presents a roll-forward of the allowance for current expected credit losses on our notes receivable for the three and six-month periods ended June 30, 2025 and 2024 (in thousands):

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