(a) Any person who has retired from the service of the state under any provision of the tier II plan and who is reemployed on a permanent basis shall resume membership in the tier II plan and shall receive credit for service for the period of such reemployment.

(b) No member reemployed under this section or otherwise reentering state service shall receive a retirement income during such member’s reemployment or other state service except (1) if such member’s services are rendered for not more than ninety working days in any one calendar year, provided that any member reemployed for a period of more than ninety working days in one calendar year shall reimburse the state retirement fund for retirement income payments received during such ninety working days; (2) if such member’s services are as a member of the General Assembly, such member’s retirement income payments shall not be suspended; or (3) if such member’s preretirement services which counted towards such member’s retirement are other than as a special deputy sheriff pursuant to chapter 78, and if such member’s postretirement services are as a special deputy sheriff or, on and after December 1, 2000, as a judicial marshal, and such member was employed as a special deputy sheriff on July 1, 1999.

(c) Upon the subsequent retirement of a member who has been reemployed, his retirement income shall be recomputed on the basis of his total period of credited service, excluding any period for which a retirement income was paid under subdivision (1) or (2) of subsection (b) of this section, and with his final average earnings recomputed on the basis of his three highest-paid years of his total state service. Notwithstanding the above, his retirement income upon such subsequent retirement shall not be less than his original retirement income as increased by any cost-of-living adjustments which occurred or would have occurred but for his reemployment after such original retirement.