Mercury Systems Inc

Item 2.02. Results of Operations and Financial Condition. On November 10, 2026, Mercury Systems, Inc. (the “Company”) issued a press release and an earnings presentation regarding its financial results for the first quarter ended October 2, 2026. The Company’s press release and earnings presentation are attached as exhibits 99.1 and 99.2 to this Current Report on Form 8-K and incorporated by reference herein. Information in Item 2.02 of this Current Report on Form 8-K and the exhibits 99.1 and 99.2 attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, regardless of any general incorporation language in such filing. Use of Non-GAAP Financial Measures In addition to reporting financial results in accordance with generally accepted accounting principles, or GAAP, the Company provides adjusted EBITDA, adjusted income, adjusted EPS, and free cash flow, which are non-GAAP financial measures. Adjusted EBITDA, adjusted income, and adjusted EPS exclude certain non-cash and other specified charges. The Company believes these non-GAAP financial measures are useful to help investors more completely understand its past financial performance and prospects for the future. However, the presentation of these non-GAAP financial measures is not meant to be considered in isolation or as a substitute for financial information provided in accordance with GAAP. Management believes these non-GAAP financial measures assist in providing a more complete understanding of the Company’s underlying operational results and trends, and management uses these measures along with the corresponding GAAP financial measures to manage the Company’s business, to evaluate its performance compared to prior periods and the marketplace, and to establish operational goals.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. Chief Operating Officer On November 10, 2026, the Company announced the formalization of David E. Farnsworth’s role as Chief Operating Officer in addition to his responsibilities as the Company’s Executive Vice President and Chief Financial Officer. In connection with this appointment, Mr. Farnsworth will receive a restricted stock unit award with an aggregate value of $500,000 in the form of shares of the Company’s common stock under the Company’s 2025 Long Term Incentive Plan. The number of shares covered by such award will be determined by dividing the dollar amount of the award by the average closing price of the Company’s common stock during the 30 calendar days prior to November 16, 2026, the grant date, and such shares shall vest in equal installments on each of the first three anniversaries of the grant date. The terms and conditions of the award are identical to the RSUs granted to the Company’s other named executive officers on August 17, 2026. There were no other changes to his compensation related to this additional role. Chief Accounting Officer On November 4, 2026, Douglas Munro, the Company’s Senior Vice President and Chief Accounting Officer, informed the Company that he has accepted a role outside the Company and that his last day would be November 13, 2026. His decision was not the result of any disagreement relating to the Company’s operations, policies, or practices. On November 10, 2026, the Company announced that Brian Caulfield has been appointed as acting Chief Accounting Officer effective as of November 13, 2026. Reporting to David E. Farnsworth, the Company’s Executive Vice President, Chief Financial Officer, and Chief Operating Officer, Mr. Caulfield will be responsible for the Company’s accounting operations and financial reporting on an interim basis while the Company conducts a search for a permanent Chief Accounting Officer. Mr. Caulfield, age 39, joined the Company in 2014 and most recently served as the Company’s Corporate Controller from 2024 to date. Prior to that he served as the Company’s Assistant Corporate Controller from 2022 to 2024, and from 2014 to 2022 he held roles of increasing leadership in the Company’s accounting function. Prior to joining the Company, Mr. Caulfield held various positions in public accounting at Ernst & Young. He has an MBA from Rivier University and a B.S. in Accounting from Fairfield University and holds his CPA license in Massachusetts. In connection with this interim position, Mr. Caulfield has entered into a $50,000 retention bonus agreement, payable in 50% increments on May 13, 2027 and November 13, 2027, contingent on his continued employment (or prior termination by the Company without cause) as of those dates. There were no other changes to his compensation related to this interim role. There are no family relationships between Mr. Caulfield and any director or executive officer of the Company, and he has no direct or indirect material interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K.