10 U.S.C. § 9325

(a) For the purpose of determining whether an enlisted member of the Air Force or the Space Force may be retired under section 9314 or 9317 of this title, his years of service are computed by adding all active service in the armed forces. (b) Time required to be made up under section 972(a) of this title may not be counted in computing years of service under subsection (a).