(a) A member who retires from an employer as defined by Section 821.001(7) based on service or a disability is entitled to membership service credit in the retirement system for the member’s state personal or sick leave that has accumulated and is unused on the last day of employment pursuant to the terms of this section. State personal or sick leave is creditable in the retirement system in the amount of one year of service credit for 50 days or more, or 400 hours or more, of accumulated state personal or sick leave. An accumulation of less than 50 days is not creditable. Not more than five days of unused state personal or sick leave may be accumulated per year. Credit established under this section may be used only for the purpose of calculating benefits under Section 824.203.
(b) The employer shall, under rules adopted by the retirement system, certify the amount of a member’s accumulated state personal or sick leave on the last day of employment before retirement.

(c) On receipt of a certification under Subsection (b) and payment under Subsection (d) of this section, the retirement system shall grant any credit to which a retiree who is a subject of the certification is entitled. Unless a member declines to purchase service credit under this section as provided by Subsection (d-1), an annuity payment may not begin until the retirement system is paid the full cost of the service credit.
(d) In order to receive credit, the member shall pay to the retirement system at the time service credit is granted under this section the actuarial present value of the additional standard retirement annuity benefits under the option selected by the member that would be attributable to the conversion of the unused state personal or sick leave into the service credit based on rates and tables recommended by the actuary and adopted by the board of trustees. Except as provided by this subsection, the retirement system must receive the payment for service credit under this section not later than the 90th day after the date the retirement system issues a cost statement for the purchase of service credit under this section. The retirement system may grant a member a one-time extension of not more than 30 days to complete the purchase of the service credit if the purchase is made by:
(1) a rollover distribution from another eligible retirement plan; or
(2) a direct trustee-to-trustee transfer of funds from:
(A) an eligible deferred compensation plan described by Section 457(b), Internal Revenue Code of 1986, that is maintained by an eligible governmental employer; or
(B) an annuity contract described by Section 403(b), Internal Revenue Code of 1986, that is purchased under a governmental plan.
(d-1) A member who fails to make the payment described by Subsection (d) within the time prescribed by that subsection may:
(1) decline to purchase service credit under this section and maintain the member’s effective date of retirement; or
(2) revoke the member’s retirement as provided by Section 824.005(a) and select a later retirement date that provides the member with sufficient time to complete the purchase of the service credit under this section.
(e) In accordance with local policy, the employer from which the retiring member was compensated on the member’s last day of employment may reimburse an employee for all or part of the cost of purchasing service credit under this section.