IMPINJ INC Debt Disclosure

Note 8. Long-term debt

In November 2021, we issued $287.5 million aggregate principal amount of convertible promissory notes due May 15, 2027 (the “2021 Notes”) and in September 2025, we issued $190.0 million aggregate principal amount of convertible promissory notes due September 15, 2029 (the “2025 Notes” and collectively, the “Notes”).

The Notes are senior unsecured obligations, do not contain any financial covenants. Each series of Notes is governed by an indenture (collectively, the “Indentures”). The 2025 Notes do not bear regular interest and the principal amount of the 2025 Notes does not accrete. The total net proceeds from the 2021 Notes and the 2025 Notes, after deducting initial debt issuance costs, fees and expenses, were $278.4 million and $183.6 million, respectively. We used approximately $183.6 million of the 2021 Notes net proceeds, excluding accrued interest, to repurchase approximately $76.4 million aggregate principal amount of convertible notes due 2026 (the “2019 Notes”) through individual privately negotiated transactions concurrent with us offering the 2021 Notes. We used approximately $17.6 million, excluding accrued interest, to repurchase the remaining $9.9 million aggregate principal amount of the 2019 Notes in June 2022. We used the remainder of the net proceeds from the 2021 Notes for general corporate purposes. We used the 2025 Notes net proceeds, and cash on hand to exchange $190.0 million aggregate principal amount of the 2021 Notes for approximately $190.0 million in cash, representing the principal amount exchanged, and approximately 811,000 shares of our common stock, representing the exchange value in excess thereof, and also paid accrued and unpaid interest thereon, in privately negotiated transactions concurrently with the 2025 Notes offering.

Terms of the Notes

The holders of each series of Notes may convert their respective Notes at their option at any time prior to the close of business on the business day immediately preceding the respective conversion dates under the following circumstances:

Regardless of the foregoing circumstances, holders may convert all or any portion of the 2021 Notes, in increments of $1,000 principal amount, on or after February 15, 2027, and may convert all or any portion of the 2025 Notes, in increments of $1,000 principal amount, on or after June 15, 2029, until the close of business on the second scheduled trading day immediately preceding the maturity date for the applicable series of Notes.

We may redeem all or any portion of the 2021 Notes for cash, at our option, on or after November 20, 2024, and all or any portion of the 2025 Notes for cash, at our option, on or after March 20, 2028, if the last reported sale price of our common stock has been at least 130% of the conversion price for the applicable series of Notes for at least 20 trading days (whether or not consecutive) during any 30

consecutive trading day period at a redemption price equal to 100% of the principal amount of the Notes being redeemed, plus any accrued and unpaid interest to, but excluding, the redemption date for such Notes.

Holders who convert their Notes in connection with certain corporate events that constitute a make-whole fundamental change (as defined in the Indenture governing each series of Notes) are, under certain circumstances, entitled to an increase in the conversion rate for such Notes. Additionally in the event of a corporate event constituting a fundamental change (as defined in the Indenture governing each series of Notes), holders of the Notes may require us to repurchase all or a portion of their Notes of such series at a repurchase price equal to 100% of the principal amount of the Notes of such series being repurchased, plus any accrued and unpaid interest to, but excluding, the repurchase date.

Our common stock exceeded 130% of the conversion price of the 2021 Notes for more than 20 trading days during the 30 consecutive trading days ended December 31, 2025. Accordingly, the 2021 Notes are convertible at the option of the holders as of December 31, 2025 and therefore, are classified as current portion of long-term debt on the consolidated balance sheet as of December 31, 2025. The “if-converted value” exceeded the principal amounts by $55.3 million based on the closing price of our common stock of $174.01 as of December 31, 2025.

Accounting for the Notes

We account for each series of Notes as a single liability measured at its amortized cost. We presented the 2021 Notes total issuance costs of $9.1 million as a direct deduction from the face amount of the 2021 Notes and amortized the issuance costs to interest expense over the respective term of the 2021 Notes using the effective interest rate method. We presented the 2025 Notes total issuance costs of $6.3 million as a direct deduction from the face amount of the 2025 Notes and amortized the issuance costs to interest expense over the respective term of the 2025 Notes using the effective interest rate method.

Accrued interest related to the 2021 Notes as of December 31, 2025 and 2024 was $0.1 million and $0.4 million, respectively. There is no accrued interest for the 2025 Notes. We record accrued interest in accrued liabilities in our consolidated balance sheet.

We estimate the fair value of the 2021 Notes to be $159.1 million and $408.7 million as of December 31, 2025 and 2024, respectively, which we determined through consideration of quoted market prices. We estimate the fair value of the 2025 Notes to be $195.6 million as of December 31, 2025, which we determined through consideration of quoted market prices. The fair value for the Notes is classified as Level 2, as defined in Note 2.

Capped Call Transactions

In connection with issuing the 2019 Notes and the 2025 Notes, we entered into privately negotiated capped call transactions with certain financial counterparties. The capped call transactions are generally expected to reduce the potential dilution to our common stock upon any conversion of the 2019 Notes or the 2025 Notes, and/or offset any cash payments we would be required to make in excess of the principal amount of converted 2019 Notes or 2025 Notes, as the case may be, with such reduction and/or offset subject to a cap based on the cap price. If, however, the market price per share of our common stock exceeds the cap price of the respective capped call transactions, then our stock would experience some

dilution and/or such capped call transactions would not fully offset the potential cash payments, in each case, to the extent the then-market price per share of our common stock exceeds the cap price.

The capped call transactions entered into in connection with the 2019 Notes, remains outstanding even though we have repurchased the 2019 Notes, to reduce the potential dilution of the remaining 2021 Notes. The initial cap price of these capped call transactions is $54.20 per share, subject to certain adjustments under the terms of these capped call transactions. These capped call transactions expire over 40 consecutive scheduled trading days ending on December 11, 2026.

The initial cap price of the capped call transactions, entered into in connection with the 2025 Notes, is $340.32 per share, subject to certain adjustments under the terms of these capped call transactions. These capped call transactions expire on September 15, 2029. The cost of $11.2 million incurred in connection with the 2025 capped call was recorded as a reduction to additional paid-in capital.

The capped call transactions are separate transactions, and not part of the terms of the 2019 Notes or the 2025 Notes. These transactions meet the criteria for classification in equity, are not accounted for as derivatives and are not remeasured each reporting period.

Partial Exchange of the 2021 Notes

In September 2025, we entered into privately-negotiated exchanges with certain holders of our outstanding 2021 Convertible Notes with respect to the exchange of $190.0 million principal amount of the 2021 Convertible Notes (the “2021 Note Exchange”).We accounted for the 2021 Note Exchange transaction as an induced conversion in accordance with Accounting Standards Codification 470-20, Debt with Conversion and Other Options (ASC 470-20), as amended for ASU 2024-04, which we early adopted on January 1, 2025, using the prospective transition approach. In connection with the induced conversion, we paid approximately $190.0 million in cash, representing the principal amount exchanged, issued approximately 811,000 shares of our common stock, representing the exchange value in excess thereof, and also paid accrued and unpaid interest thereon. As a result of the induced conversion, we recorded $15.0 million in induced conversion expense which is included in the Consolidated Statements of Operations for the year ended December 31, 2025. We did not receive any cash proceeds from issuing the shares of common stock but recognized additional paid-in-capital of $13.1 million representing the induced conversion expense, net of approximately $2.0 million of unamortized debt issuance costs related to the converted 2021 Notes.