(1) The board must have the applicant examined during the fifth or sixth month of disability leave. The examination is to be performed by the board doctor or a specialist selected by the board doctor. The board shall not approve the disability retirement without this examination unless:

(a) The applicant establishes that the disabling condition will exist for at least six months; and

(b) The applicant voluntarily waives disability leave.

(2) Following receipt of the examination report, the board must:

(a) Review the medical evidence and all relevant information about the applicant's fitness for duty;

(b) Consider the duties of the applicant's position; and

(c) Consider any other pertinent evidence.

The board must either grant or deny disability retirement based on the evidence or return the applicant to duty for a reasonable period of trial service.

(3) If the board cannot determine with reasonable certainty whether or not the applicant is disabled, the board may issue a written order that the applicant is to return to duty for a reasonable period of trial service to determine the applicant's fitness for active duty.

(a) The length of the trial service period must be supported by medical evidence.

(b) During the period of trial service the applicant is to return to the same duties in the same position held at the time of discontinuance of service.

(c) If the applicant is found to be disabled, the board is not to grant a second six-month period of disability leave, but is to return the applicant to disability leave status for the remainder, if any, of the initial six-month leave period.