(1) A member who is a conservation officer may retire under this section if all of the following requirements are met:

    (a) The member is a conservation officer on April 1, 1991.

    (b) The member has 25 or more years of credited service, of which 20 years of credited service are as a conservation officer and of which the last 2 years of credited service are as a conservation officer.

    (2) A member who is a conservation officer may retire under this section if the member has 25 or more years of credited service, of which 23 years of credited service are as a conservation officer and of which the last 2 years of credited service are as a conservation officer.

    (3) A member may retire under subsection (1) or (2) upon written application to the retirement board stating a date upon which he or she desires to retire. Subject to section 20j, beginning on the retirement allowance effective date, he or she shall receive a retirement allowance equal to 60% of the member’s annual compensation for the member’s most highly compensated 24 consecutive months of service as a conservation officer. The formula for calculating a member’s retirement allowance under this subsection shall never exceed the formula for calculating a retirement allowance under section 24 of the state police retirement act of 1986, 1986 PA 182, MCL 38.1624.

    (4) A member who is a conservation officer may retire under this section if all of the following requirements are met:

    (a) The member is a conservation officer on April 1, 1991.

    (b) The member is 50 years of age or older.

    (c) The member has 10 years of credited service as a conservation officer and the last 2 years of credited service are as a conservation officer.

    (5) A member may retire under subsection (4) upon written application to the retirement board, on or after April 1, 1991, but not later than April 1, 1992, stating a date on which he or she desires to retire. The retirement allowance effective date shall be on or after May 1, 1991 but not later than July 1, 1992. Beginning on the retirement allowance effective date, he or she shall receive a retirement allowance equal to 2% of the member’s annual compensation for the member’s most highly compensated 24 consecutive months of service as a conservation officer times the number of years, including any fraction of a year, of service credited to the member under this act. However, a retirement allowance payable under this subsection shall not exceed 60% of the member’s annual compensation for the member’s most highly compensated 24 consecutive months of service as a conservation officer.

    (6) Before the effective date of the retirement allowance, a member who is a conservation officer and who retires under this section shall elect to receive his or her retirement allowance under a form of payment as provided in section 31(1).

    (7) Pursuant to rules promulgated by the retirement board, a member who retires under this section before becoming 65 years old may elect to have his or her regular retirement allowance equated on an actuarial basis to provide an increased retirement allowance payable to age 65 and a reduced retirement allowance payable after becoming 65 years old. The retirant’s increased retirement allowance payable to age 65 shall approximately equal the sum of his or her reduced retirement allowance payable after age 65 and his or her estimated social security primary insurance amount.

    (8) If a member who retires under this section dies before receiving payment of his or her retirement allowance in an aggregate amount equal to the accumulated contributions standing to the retirant’s account in the employees’ savings fund at the time of his or her retirement, the difference between his or her accumulated contributions and the amount of the retirement allowance received by him or her shall be paid to the person or persons that the retirant has nominated by written designation duly executed and filed with the retirement board, or, if there is no such designated person or persons surviving, then to the retirant’s legal representative or estate.

    (9) The director of the department of natural resources, or his or her designee, shall certify to the retirement board that a member who applies to retire under this section is a conservation officer.

    (10) This section does not prohibit a member who is a conservation officer and who does not meet the requirements of this section from qualifying for a retirement allowance under any other provision of this act.