Record of Military Service for Members of the Armed Forces Act of 2021 This bill requires the Department of Defense (DOD) to create the Certificate of Military Service. The Certificate of Military service will be a standard record of military service for all members of active and reserve components of the armed forces to encompass all duty, including that of National Guard and Coast Guard duty. Under the bill, the document must (1) be standardized, (2) be the same for all members of the armed forces, and (3) replace and serve the same function as a discharge certificate or certificate of release (DOD Form DD-214). The bill also requires that a current record of service be issued to members of the reserve components upon the occurrence of any of the following events: permanent change to duty status (e.g., retirement or transfer to active duty), discharge or release from temporary active duty orders, specified promotions, and transfer to another state National Guard.