(a) An eligible member may establish service credit in the retirement system for military service performed that is creditable in the retirement system.
(b) A member eligible to establish military service credit is one who:
(1) currently contributes to the retirement system;
(2) has at least 8 years of service credit in the retirement system; and
(3) does not receive and is not eligible to receive federal retirement payments based on 20 years or more of active federal military duty or its equivalent.
(c) Military service creditable in the retirement system is active duty federal military service.
(d) A member may establish one month of service credit for each month or fraction of a month of duty, but not more than 48 months of service credit in the retirement system for military service.
(e) A member may establish credit under this section by depositing with the retirement system a contribution computed for each month of military service claimed at the rate of six percent of the member's current monthly state salary.