(a) An eligible member may establish credit under Section 853.501 by filing written application therefor with the retirement system, accompanied by satisfactory evidence of the member's military service.
(b) An eligible member seeking military service credit under Section 853.502 must file with the retirement system a written application for the credit, together with satisfactory evidence of the member's military service.
(c) No person may obtain credit under this subchapter for more than 60 months of military service.