(a) A member may apply for a disability retirement annuity by:
(1) filing an application for retirement with the board of trustees; or
(2) having an application filed with the board by the member's employer or legal representative.
(b) An application for a disability retirement annuity may not be filed later than the date specified by the member for retirement or earlier than the 90th day before that date.
(c) An applicant must submit to medical examination as required by the medical board.
(d) A member may not apply for a disability retirement annuity under this subchapter after the date the member's participating municipality begins participation in the occupational disability benefits program under Subchapter E.