10 U.S.C. § 640: Deferment of retirement or separation for medical reasons

(a) If the Secretary of the military department concerned determines that the evaluation of the physical condition of an officer and determination of the officer’s entitlement to retirement or separation for physical disability require hospitalization or medical observation and that such hospitalization or medical observation cannot be completed with confidence in a manner consistent with the member’s well being before the date on which the officer would otherwise be required to retire or be separated under this title, the Secretary may defer the retirement or separation of the officer under this title. (b) A deferral of retirement or separation under subsection (a) may not extend for more than 30 days after completion of the evaluation requiring hospitalization or medical observation.