Md. Code, State Pers. & Pens. § 26-307

(a) (1) In the year of retirement, a member may purchase service credit for eligibility service of up to 10 years for periods of employment for which the member: (i) would have been entitled to purchase the service credit under the Employees’ Pension System; and (ii) is not otherwise entitled to service credit under the Law Enforcement Officers’ Pension System. (2) To purchase service credit under this section, a member must: (i) complete a claim for the service credit and file it with the Board of Trustees on the form that the Board of Trustees provides; and (ii) pay to the Board of Trustees an amount equal to the annuity reserve and pension reserve required to fund the additional allowance. (b) (1) A member may purchase credit for eligibility service for previous service in a position described in § 23-204(a) of this article. (2) To purchase the service credit, the member must pay, in a single payment, the contributions, with interest, that the Board of Trustees considers appropriate.