Winchester Bancorp, MHC will be formed as the Massachusetts-chartered mutual holding company of Winchester Bancorp, Inc. in connection with the reorganization of Winchester Savings Bank into the “two-tier”mutual holding company form of organization. Upon completion of the reorganization and offering, Winchester Bancorp, MHC will own 55% of Winchester Bancorp, Inc.’s common stock. As a mutual holding company, Winchester Bancorp, MHC will be a non-stock company that will be required by law to own a majority of the outstanding voting stock of Winchester Bancorp, Inc. for so long as Winchester Bancorp, MHC remains in existence. Winchester Bancorp, MHC, through its board of trustees, will be able to exercise voting control over virtually all matters put to a vote of stockholders of Winchester Bancorp, Inc. Winchester Bancorp, MHC will be subject to comprehensive regulation and examination by the Massachusetts Commissioner of Banks and the Board of Governors of the Federal Reserve System (the “Federal Reserve Board”). Winchester Bancorp, Inc. is a Maryland corporation that was incorporated in December 2024. The offering of common stock is being made by Winchester Bancorp, Inc. in connection with the reorganization of Winchester Savings Bank into the “two-tier” mutual holding company form of organization. Winchester Bancorp, Inc. will become the bank holding company for Winchester Savings Bank by owning all the outstanding shares of capital stock of Winchester Savings Bank. To date, Winchester Bancorp, Inc. has engaged in organizational activities only. Following the reorganization and offering, Winchester Bancorp, Inc.’s primary business activity will be to own all the outstanding shares of capital stock of Winchester Savings Bank. Winchester Bancorp, Inc. will be authorized to engage in any other business activities that are permissible for bank holding companies under Massachusetts and federal law. Upon completion of the reorganization and offering, Winchester Bancorp, MHC will own 55% and public stockholders will own 43% of Winchester Bancorp, Inc.’s common stock. Public stockholders will not be able to exercise voting control over most matters put to a vote of stockholders. In addition, as a “controlled company” under the meaning of the Nasdaq Stock Market corporate governance rules following the offering, Winchester Bancorp, Inc. will be exempt from certain corporate governance requirements, including the requirement that a majority of our board of directors be independent under Nasdaq Stock Market listing standards, and that executive compensation and director nominations be overseen by independent directors. Winchester Bancorp, Inc. will be subject to comprehensive regulation and examination by the Massachusetts Commissioner of Banks and the Federal Reserve Board. Winchester Bancorp, Inc.’s website address will be www.winchestersavings.com. Winchester Savings Bank is a Massachusetts-chartered savings bank headquartered in Winchester, Massachusetts. Winchester Savings Bank was originally chartered in 1871, and operates from its main office and four full-service branch offices in eastern Massachusetts, located in Arlington, Danvers and Woburn. Winchester Savings Bank’s subsidiaries are Sachem Holdings, Inc., Aberjona Holdings, Inc., 1871 Company, LLC, and Wedgemere Holdings, LLC. Sachem Holdings, Inc. and Aberjona Holdings, Inc. are Massachusetts security corporations established to hold investment securities. 1871 Company, LLC’s principal activity is the holding of bank premises. Wedgemere Holdings, LLC’s principal activity is the holding of properties acquired in settlement of loans. We consider Middlesex County and, to a lesser extent, Essex County, as our primary market area for gathering deposits. We consider Middlesex County as well as the surrounding counties located in Massachusetts as our primary market area for lending. Our business consists primarily of taking deposits from the general public and investing those deposits, together with funds generated from operations, in one- to four-family residential real estate loans, multi-family residential real estate loans, construction loans, commercial real estate loans, home equity loans and lines of credit, commercial business loans and consumer loans, as well as in investment securities. Winchester Savings Bank is subject to comprehensive regulation and examination by the Massachusetts Commissioner of Banks and the Federal Deposit Insurance Corporation (the “FDIC”). Winchester Savings Bank’s main office is located in Winchester, Massachusetts.