On March 4, 2024, the Company received the Pre-Paid Advance of $10,000,000 from Yorkville and issued Yorkville the Yorkville Note in the amount of $10,000,000 for such Pre-Paid Advance that was originally due 15 months from the date of issuance, and interest shall accrue on the outstanding balance of the Yorkville Note at an annual rate equal to 6%, subject to an increase to 18% upon an event of default as described in the Yorkville Note. The Yorkville Note is convertible by Yorkville into shares of the Company's common stock. As consideration for the Pre-Paid Advance, immediately prior to, and substantially concurrently with, the closing of the Business Combination, QT Imaging issued to Yorkville that number of shares of QT Imaging which converted in the aggregate into 1,000,000 shares of the Company's common stock upon the completion of the Business Combination. In accordance with Accounting Standards Codification (“ASC”) 470-20, the proceeds of $10,000,000 were recorded between the promissory note and common stock less debt origination costs of $975,000, consisting of a $375,000 commitment fee for the SEPA

and an original issue discount of 6% for the Yorkville Note, on a relative fair value basis. Expenses related to a structuring fee was $0 and $20,000 for the three and six months ended June 30, 2024, respectively, and was included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. As noted in Note 3 - the Pre-Paid Advance contained Derivatives that were bifurcated and recorded a separate instrument. The initial value of the Derivatives of the $5,120,900 was recorded as a debt discount against the Pre-Paid Advance.

Under the terms of the original Yorkville Note, a “Trigger Event” shall occur if the daily VWAP is less than the Floor Price for five trading days during a period of seven consecutive trading days (a “Floor Price Trigger” and the last such day of such occurrence, a “Trigger Date”). If, at any time six months after the issuance of the Yorkville Note, a Trigger Event occurs, then the Company will be obligated to make monthly payments in an amount equal to the sum of (i) $1,500,000 of principal in the aggregate among all promissory notes issued to Yorkville (or the outstanding principal if less than such amount) (the “Triggered Principal Amount”), plus (ii) a payment premium of 5% in respect of such Triggered Principal Amount, and (iii) accrued and unpaid interest hereunder as of each payment date beginning on the 5th trading day after the Trigger Date and continuing on the same day of each successive calendar month to Yorkville pursuant to the terms of the Yorkville Note. However, in the event that the Company shall be required to make such cash payments to Yorkville under the Yorkville Note as a result of the occurrence of a Trigger Event, the Company shall be entitled upon written notice to Yorkville, to direct that Yorkville (i) if Yorkville has sold the Company Shares that it received upon the completion of the Merger to apply, in accordance with the terms of the Yorkville Note, up to 50% of Yorkville’s net sale proceeds of the Company Shares to satisfy, in part or in whole, the Triggered Principal Amount of such cash payments due to Yorkville or (ii) or if Yorkville has not sold the Company Shares, to apply up to 50% of the value of the Company Shares on such date the cash payment is due based on the VWAP as quoted by Bloomberg LP of the Company Shares as an offset of the Triggered Principal Amount of the cash payments due to Yorkville. The obligation of the Company to make monthly prepayments due to the occurrence of a Floor Price Triger shall cease (with respect to any payment that has not yet come due) if any time after the Trigger Date (a) the Company reduces the Floor Price to an amount that is at least 50% of the daily VWAP of the common stock or (b) the daily VWAP is greater than 110% of the Floor Price for a period of five consecutive trading days, unless a subsequent Trigger Event occurs. Furthermore, within one trading day of a Floor Price Trigger that remains after application of all amounts related to the Company Shares as described above, the Company shall reduce the Floor Price to an amount that is at least 50% of the daily VWAP of the common stock, and provide Yorkville written confirmation of such reduction of the Floor Price or be obligated to make the above monthly cash payments.

Following the effectiveness of the registration statement on Form S-1 that the Company filed to register the shares to be issued pursuant to the SEPA, the Floor Price for Yorkville was $0.8768 per share. For the first five trading days commencing after six months after the issuance of the Yorkville Note, which ended on September 11, 2024, the daily VWAP of the common stock was less than the Floor Price, and as a result, September 11, 2024 constitutes a Trigger Date, and on that Trigger Date, a Trigger Event occurred due to a Floor Price Trigger. Accordingly, on September 13, 2024, the Company made the initial payment due to Yorkville as a result of the Trigger Event that occurred on September 11, 2024 in an amount totaling $1,521,581, the calculation of which reflects a reduction to the Triggered Principal Amount by 50% of the net sale proceeds of the Company Shares by Yorkville following the closing of the Business Combination. The total payment of $1,521,581 comprised of $1,145,407 of principal, $318,904 of accrued interest, and $57,270 of 5% early payment premium.

On September 26, 2024, the Company and Yorkville entered into an Omnibus Amendment (the “Omnibus Amendment”), pursuant to which the Company and Yorkville agreed to amend certain terms of the Yorkville Note to reduce the Company’s obligations resulting from the occurrence of the Trigger Event. Pursuant to the Omnibus Amendment, the maturity date of the Yorkville Note was extended approximately six months from June 4, 2025 to December 15, 2025. Further, the Omnibus Amendment acknowledges the Company’s obligation to make monthly payments to Yorkville in the amount of the Trigger Principal Amount due to the occurrence of the Trigger Event and revised the Yorkville Note to provide that no further monthly payments will be owed during the period beginning on the date of the Omnibus Amendment and ending on January 15, 2025. In exchange for this relief, beginning on January 15, 2025, and continuing on the same day of each successive calendar month until and including November 15, 2025, whether or not a Trigger Event has occurred and is continuing as of such dates, the Company will make monthly payments in an amount equal to $500,000 plus the payment premium of 5% plus accrued and unpaid interest under the Yorkville Note as of each such payment date. Such monthly payments will not be reduced or offset by any amount, including, but not limited to, any net sales proceeds of the Company Shares or any value of the Company Shares based on the VWAP as quoted by Bloomberg, LP. The Omnibus Amendment also provided that 100% of the

proceeds of the sale of the remaining 400,000 Company Shares held at the time of entry into the Omnibus Amendment by Yorkville shall be retained by Yorkville and shall not be used to offset or reduce any amounts owed under the Yorkville Note, or to otherwise benefit the Company in any way. The Omnibus Amendment also provides that in the event that the Company’s common stock is delisted from trading on the Nasdaq Stock Market, Yorkville consents to the occurrence of such delisting from the Nasdaq Stock Market, if it is to happen, and that it will not constitute an Event of Default as defined per the Omnibus Amendment, provided that (i) the Company uses its best efforts to have its common stock relisted on the Nasdaq Stock Market as soon as possible and (ii) the Company’s common stock is listed on the OTC Markets’ OTCQX market tier within 30 days in the event that a delisting from the Nasdaq Stock Market occurs. The Omnibus Amendment was accounted for as a troubled debt restructuring, resulting in a prospective adjustment to the effective interest rate in accordance with ASC 470-60.

On October 31, 2024, the Company and Yorkville executed the Second Omnibus Amendment to the Yorkville Note (the “Second Amendment”), pursuant to which the maturity date of the Yorkville Note was extended from December 15, 2025 to March 31, 2026. Further, the Second Amendment acknowledged the Company’s obligation to make monthly payments to Yorkville in the amount of the Trigger Principal Amount due to the occurrence of the Trigger Event and no further monthly payments will be owed during the period beginning on the date of the Second Amendment and ending on February 15, 2025. In exchange for this relief, beginning on February 15, 2025, and continuing on the same day of each successive calendar month until and including February 15, 2026, whether or not a Trigger Event has occurred and is continuing as of such dates, the Company agreed to make monthly payments in an amount equal to $500,000 plus the payment premium plus accrued and unpaid interest as of each such payment date. Such monthly payments under the Second Amendment were not to be reduced or offset by any amount, including, but not limited to, any net sales proceeds of the Company Shares or any value of the Company Shares based on the VWAP as quoted by Bloomberg, LP. Further, pursuant to the terms of the Second Amendment, the Company elected to reduce the Floor Price to $0.50 per share, effective as of the date of the Second Amendment. In addition, the Second Amendment provided that to the extent that Yorkville converts any portion of the Investor Note into shares of the common stock between the date of the Second Amendment and January 15, 2025, the first $500,000 of such conversions of the Yorkville Note shall reduce the principal balance of the Yorkville Note. For the avoidance of doubt and without implication that the opposite would otherwise be true, all other conversions of the Yorkville Note pursuant to the Second Amendment were to be applied as provided for in and consistent with the terms of the Yorkville Note. The Second Amendment also provided that in the event that the common stock is delisted from trading on the Nasdaq Stock Market, Yorkville consents to the occurrence of such delisting from the Nasdaq Stock Market, if it is to happen, and that it will not constitute an Event of Default as defined per the Omnibus Amendment, provided that (i) the Company uses its best efforts to have the common stock relisted on the Nasdaq Stock Market as soon as possible and (ii) the common stock is listed on the OTC Markets’ OTCQX or OTCQB market tiers within 30 days in the event that a delisting from the Nasdaq Stock Market occurs. The Second Amendment was accounted for as a debt modification, resulting in a prospective adjustment to the effective interest rate.

On January 9, 2025, the Company and Yorkville entered into the Third Omnibus Amendment to the Yorkville Note, (the “Third Amendment”), pursuant to which, the Company and Yorkville agreed that for $1.5 million of the then current outstanding balance due under the Yorkville Note (principal and unpaid accrued interest), the fixed price for conversion shall be modified to $0.584 per share, and for the remainder of the balance, the fixed price shall not be changed but shall remain $4.61395 per share as provided for in the Yorkville Note when the Company issued it on March 4, 2024. Further, the Third Amendment removed the Company’s obligation to make monthly payments to Yorkville, previously owing due to the occurrence of the Trigger Event, such that no further monthly payments will be owed during the period beginning on the date of the Third Amendment and ending on the maturity date of the Yorkville Note of March 31, 2026. In exchange for this relief, the aggregate purchase price owed to the Company from the first Advance that occurs pursuant to the terms of the SEPA (the “Advance Proceeds”) shall be paid by Yorkville offsetting the amount of the Advance Proceeds against an equal amount outstanding under the Yorkville Note (first towards accrued and unpaid interest, and then towards outstanding principal and the corresponding payment premium in respect of such principal amount, if applicable), and that for any subsequent Advances pursuant to the terms of the SEPA, Yorkville shall pay half of such Advance Proceeds directly to the Company and the other half of such Advance Proceeds shall be paid by Yorkville offsetting the amount of the Advance Proceeds against an equal amount outstanding under the Yorkville Note (first towards accrued and unpaid interest, and then towards

On February 26, 2025, the Company used a portion of the proceeds of the Lynrock Lake Term Loan to pay Yorkville an amount equal to $3,000,000 in cash and issued to Yorkville a warrant to purchase 15,000,000 shares of its common stock at an exercise price of $0.40 per share pursuant to the Yorkville Warrant to fully settle and discharge the Company’s obligations under the Yorkville Note and extinguish the Yorkville Note as having been fully performed. The Yorkville Warrant is exercisable until February 26, 2030. The Company and Yorkville also entered into that certain Termination Agreement, dated February 26, 2025, pursuant to which the parties acknowledged the termination of the SEPA effective February 26, 2025. The fair value of the Yorkville Warrant at issuance amounted to $2,992,522. As a result of the extinguishment of the Yorkville Note, the Company recorded an expense of $0 and $1,940,216, respectively, in other income (expense), net within the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2025.

In February 2024, GigCapital5 and QT Imaging entered into the Cable Car Note with Cable Car, pursuant to which Cable Car agreed to advance $1,500,000 at the closing of the Business Combination, as was evidenced by the Loan, dated March 4, 2024, by and between QT Imaging and Cable Car. The Cable Car Note does not bear interest, and is due and payable 13 months after issuance, unless the time for payment is accelerated as a result of an event of default. As full compensation to Cable Car for the Loan to QT Imaging in lieu of any simple or in-kind interest on the Loan, QT Imaging issued to Cable Car that number of shares of QT Imaging which at the completion of the Business Combination would be converted in accordance with the terms of the Business Combination Agreement into 180,000 shares of the Company's common stock. In accordance with ASC 470-20, the proceeds of $1,500,000 were recorded between the promissory note and common stock less debt origination costs of $40,740, consisting of legal fees, on a relative fair value basis.

On January 9, 2025, the Company and Cable Car entered into an Omnibus Amendment (the “Cable Car Amendment”) to amend certain terms of the Cable Car Note, including a reduction of the conversion price for the Cable Car Note to $0.584 per share. Further, the Cable Car Amendment provides that the maturity date for the Cable Car Note shall be extended to March 31, 2026, in consideration for which, the Company shall pay an extension fee (the “Extension Fee”) of $90,000 to Cable Car, with such fee being added to the amount due and payable on such maturity date, unless the Cable Car Note is earlier converted pursuant to its terms, in which event the Extension Fee shall also be converted. No interest shall accrue or be due on the Extension Fee. Pursuant to the Cable Car Amendment, interest shall accrue on the outstanding principal balance of the Cable Car Note at an annual rate equal to 6%, with interest being calculated based on a 365-day year and the actual number of days elapsed, to the extent permitted by applicable law. Interest shall be due and payable on the maturity date for the Cable Car Note, unless the Cable Car Note is earlier converted pursuant to its terms, in which event such accrued and unpaid interest shall also be converted. In addition, in connection with any sale, assignment, transfer, or other disposition (a “Cable Car Sale”) of any shares into which the Cable Car Note is converted pursuant to its terms, the Cable Car Amendment provides that to the extent such Cable Car Sale is made pursuant to Rule 144, provided that Rule 144 is available as an exemption from the registration requirements for such Cable Car Sale, if requested by Cable Car and upon delivery by Cable Car of such customary representations and other documentation reasonably acceptable to the Company in connection with transactions relying upon Rule 144, the Company shall use commercially reasonable efforts to cause its transfer agent to remove any restrictive legends related to the book entry account holding such shares sold or disposed of by Cable Car without restrictive legends within two business days of such request. The Company recorded the Extension Fee of $0 and $90,000 in other income (expense), net within the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2025.

On February 26, 2025, the Company entered into the Credit Agreement that provides the Lynrock Lake Term Loan with Lynrock Lake. The Credit Agreement is secured by a first priority lien on substantially all assets of the Company and provides for a term loan in the aggregate principal amount of $10,100,000 at an interest rate of 10.0% per annum, compounded quarterly. The maturity date of the Credit Agreement is March 31, 2027. The Lynrock Lake Term Loan shall be repaid on the maturity date in an amount equal to the aggregate principal amount outstanding, together with all accrued and unpaid interest and any outstanding and payable fees.

Subject to the payment of the Make-Whole Amount (as defined in the Credit Agreement), the Company may at any time prior to the maturity date optionally prepay the term loan, in full or in part, upon irrevocable written notice of three business days prior to the proposed prepayment; provided that if such prepayment is to be funded with the proceeds of a refinancing or disposition, such notice of prepayment may be revoked if the financing or disposition is not consummated; provided further, that any such prepayment made in connection with, or in anticipation of, a Change of Control (as defined in the Credit Agreement) will also be subject to a prepayment premium equal to 20% of the amount of principal being prepaid (the “Prepayment Premium”). Partial prepayments of the term loan shall be in an aggregate principal amount of $250,000 or a whole multiple thereof.

• If on any date the Company or any of its subsidiaries will receive net cash proceeds in an amount equal to or exceeding (i) $250,000 in any single transaction or series of related transactions or (ii) $250,000 in the aggregate for all transactions during the term of the Credit Agreement from any Asset Sale (as defined in the Credit Agreement) or Recovery Event (as defined in the Credit Agreement) then the Company or such subsidiary shall prepay the term loan, on or prior to the date which is five business days after the date of the realization or receipt by the Company or subsidiary in an amount equal to 100% percent of such proceeds; and

There are no requirements to make any prepayment in the event that the Company sells any of its capital stock. In addition, at the option of Lynrock Lake, the Company shall also make mandatory repayments of the term loan on a monthly basis, no later than five business days after the end of each month (provided that such date for payment is prior to the maturity date), if the Company or its subsidiaries receive payment of accounts receivable on or after January 1, 2026, in an amount equal to 15% percent of the aggregate amount of payments of accounts receivable actually received during such prior month, net of any cost of collection incurred not in the ordinary course of business. No Make-Whole Amount (as defined in the Credit Agreement) or Prepayment Premium is due or payable on any such mandatory prepayment as a result of receipt of accounts receivable on or after January 1, 2026. As of

Furthermore, in connection with the Lynrock Lake Term Loan, the Company issued to Lynrock Lake the Lynrock Lake Warrant, a warrant to purchase 61,000,000 shares of its common stock at an exercise price of $0.40 per share. The Lynrock Lake Warrant is exercisable until February 26, 2035. Lynrock Lake may cashless exercise the Lynrock Lake Warrant. The Lynrock Lake Warrant is also subject to anti-dilution adjustments to the exercise price and the number of shares which may be purchased upon exercise of the Lynrock Lake Warrant in the event that the Company issues shares of common stock (or derivative securities) at a price that is either less than the $0.40 exercise price or the fair market value of a share of common stock from the immediately prior trading day. The fair value of the Lynrock Warrant at issuance amounted to $16,496,084.