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STATES\n\nSECURITIES AND EXCHANGE COMMISSION\n\nWASHINGTON, D.C. 20549\n\nFORM 10-K\n\n(Mark One)\n\n☒\n\nANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934\n\nFor the fiscal year ended March 27, 2026\n\nOR\n\n \n\n☐\n\nTRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934\n\n \n\nFor the transition period from _______________ to _______________\n\nCommission File Number: 001-39675\n\n \n\n \n\nALLEGRO MICROSYSTEMS, INC.\n\n(Exact name of registrant as specified in its charter)\n\n \n\n \n\nDelaware\n\n \n\n46-2405937\n\n(State or other jurisdiction of incorporation or organization)\n\n \n\n(I.R.S. Employer Identification No.)\n\n \n\n \n\n \n\n955 Perimeter Road\n\nManchester, New Hampshire\n\n \n\n03103\n\n(Address of principal executive offices)\n\n \n\n(Zip Code)\n\n \n\n(603) 626-2300\n\n(Registrant’s telephone number, including area code)\n\n \n\n \n\nSecurities registered pursuant to Section 12(b) of the Act:\n\n \n\nTitle of each class\n\n \n\nTrading\n\nSymbol(s)\n\n \n\nName of each exchange on which registered\n\nCommon Stock, par value $0.01 per share\n\n \n\nALGM\n\n \n\nThe NASDAQ Stock Market LLC\n\n \n\nSecurities registered pursuant to Section 12(g) of the Act: None.\n\nIndicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐\n\nIndicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒\n\nIndicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐\n\nIndicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐\n\nIndicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.\n\n \n\nLarge accelerated filer\n\n \n\n☒\n\nAccelerated filer\n\n☐\n\nNon-accelerated filer\n\n \n\n☐\n\nSmaller reporting company\n\n☐\n\n \n\n \n\n \n\nEmerging growth company\n\n☐\n\n \n\nIf an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐\n\nIndicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒\n\nIf securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐\n\nIndicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐\n\nIndicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒\n\nAs of September 26, 2025, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the voting and non-voting common equity held by non-affiliates was $3,703,521,114 based on the closing sale price as reported on The NASDAQ Stock Market LLC on such date.\n\nAs of May 18, 2026, the registrant had 186,222,406 shares of common stock, $0.01 par value per share, outstanding.\n\nDOCUMENTS INCORPORATED BY REFERENCE\n\nPortions of the registrant’s proxy statement for its 2026 Annual Meeting of Stockholders to be filed pursuant to Regulation 14A within 120 days of the end of the registrant’s fiscal year ended March 27, 2026 are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.\n\n \n\n \n\n \n\nTABLE OF CONTENTS\n\n \n\n \n\nPage\n\n \n\n[Forward Looking Statements](#forward_looking_statements)\n\n1\n\nPART I."}