Eligibility service for a member consists of service credit: for employment as a member; regained under § 25-304 of this subtitle by a member who redeposits accumulated contributions previously withdrawn; transferred from a retirement or pension system under Title 37 of this article or Title 31, Subtitle 1 of this article; for military service as provided in Title 38 of this article; purchased under this subtitle; or transferred from the Employees’ Pension System under § 25-306.1 of this subtitle.