Conn. Gen. Stat. § 5-158c

Each state employee who became a member of the state employees retirement system, part B, without having first become a member of such system, part A, shall, upon payment of such sum to the retirement system, within the time and in the manner prescribed by the State Retirement Commission, as such commission shall determine to be equitable, but not in excess of five per cent of all salaries or wages received upon which such employee's retirement salary is to be based, be deemed a member of part A and receive upon retirement, in addition to any Social Security benefits, such retirement salary as said employee would be entitled to as a member of part A of the state employees retirement system.