Conn. Gen. Stat. § 10-183p: Purchase of service credit by members who are participants in other retirement systems.

Any member who is also a participant in an alternate retirement program, as defined in subsection (u) of section 5-154, the state employees retirement system or any other retirement system may purchase service credit in the Connecticut teachers' retirement system in accordance with section 10-183e, provided such member withdraws any and all employee funds and forfeits all employer contributions and earnings thereon in the respective system, other than the Social Security System or the nonregular military retirement system under 10 USC Chapter 1223, as amended from time to time. No person shall be eligible for membership in the teachers' retirement system and any other retirement system or program at the same time for the same service.