Maryland Code, State Personnel and Pensions § 22-308

(1) eligibility service, except as provided in subsection (b) of this section; and

(2) credit for unused sick leave as provided in § 20-206 of this article.

(b)(1) Except as provided in paragraph (2) of this subsection, a member's creditable service for a period of regular part-time employment equals the member's actual employment during that period.

(2) Subject to paragraph (3) of this subsection, a member's creditable service for a period of regular part-time employment equals the member's eligibility service for that period if:

(3) Except to the extent that a disability was aggravated after a member's enrollment, paragraph (2) of this subsection does not apply to a disability incurred before a member's enrollment.