Eligibility for retirement, when — temporary-substitute service for retiree authorized, limitation, no contribution from retiree required

1. On and after the first day of July next following the operative date, any member who is sixty or more years of age and who has at least five years of creditable service, or who has attained age fifty-five and has at least twenty-five years of creditable service, or who has at least thirty years of creditable service regardless of age may retire and receive the full retirement benefits based on the member's creditable service. A member whose creditable service at retirement is less than five years shall not be entitled to a retirement allowance but shall be entitled to receive the member's contributions. 2. Any person retired and currently receiving a retirement allowance pursuant to sections 169.600 to 169.715 may be employed on either a part-time or temporary-substitute basis by a district included in the retirement system not to exceed a total of five hundred fifty hours in any one school year, without a discontinuance of the person's retirement allowance. Such a person shall not contribute to the retirement system, or to the public school retirement system established by sections 169.010 to 169.141, because of earnings during such period of employment. If such a person is employed in any capacity by such a district on a regular, full-time basis, or the person's part-time or temporary-substitute service in any capacity exceeds five hundred fifty hours in any one school year, the person shall not be eligible to receive the person's retirement allowance for any month during which the person is so employed or the retirement system shall recover the amount the person earned in excess of the limitations, whichever is less. 3. The system shall pay a monthly retirement allowance for the month in which a retired member or beneficiary receiving a retirement allowance dies.