(a) Except as provided by Subsection (b) and § 853.0015, the governing body of a participating municipality by ordinance may authorize the crediting in the retirement system of updated service credits for service performed for the municipality by members. Beginning January 1, 2022, a member must be a contributing employee of the municipality on the date prescribed by § 853.402(e) to be eligible to receive an updated service credit authorized under this section. An updated service credit authorized under this section replaces any updated service credit or prior service credit previously authorized for part of the same service.
(b) A municipality may not authorize updated service credits for members who had less than 36 months of credited service on the date prescribed by § 853.402(e).

(c) In adopting an ordinance under this section, a governing body shall specify the percentage of base updated service credits to be used in computing updated service credits for employees of the municipality and shall specify the date the updated service credits will take effect. The percentage adopted may be 50 percent, 75 percent, or 100 percent of a base updated service credit. The effective date must be January 1 of a year specified by the governing body. If the governing body of a municipality has specified a different percentage in an ordinance adopted under § 853.404(a) and in effect on December 31, 1999, the percentage used in computing updated service credits for employees of that municipality remains in effect until changed or discontinued under § 853.404.
(d) A governing body that adopts an ordinance under this section shall send it to the retirement system, and the system must receive it before the effective date of the updated service credits authorized in the ordinance.