Conn. Gen. Stat. § 5-165a

(b) If a member who has terminated with at least twenty-five years of service or retired pursuant to section 5-162 , 5-163a , 5-173 or 5-188 , but whose benefits in either event are not yet being paid, dies prior to the commencing date of his benefits, his spouse, provided they have been lawfully married for at least the twelve months preceding his death, shall receive a lifetime income equal to fifty per cent of the average of the retirement income that the member would have been entitled to if his benefits had commenced the date he died had his benefit been paid under the option specified in said subdivision (4) and the retirement income that the member would have been entitled to with such benefits being paid under the option specified in said subdivision (1). If such member was not eligible to retire at the time of his death, such benefit shall be calculated as if he had reached age fifty-five. The first payment shall be made as of the first day of the month coincident with or, otherwise, next following his date of death.

(c) If a member who has completed the age and service requirements for retirement under section 5-162 , 5-163a , 5-173 or 5-188 , and who has elected to receive his retirement benefits under subdivision (2) or (3) of subsection (a) of section 5-165 , dies prior to the effective date of commencement of benefits but within ninety days after he first elects to receive his retirement benefits under subdivision (2) or (3) of said subsection (a), then his beneficiary or contingent annuitant shall receive an income in an amount equal to the benefit that would have been payable to the survivor had the member retired the day he died and had his benefit been paid under the option he had elected at the time of his death. This subsection shall not apply after ninety days after the date the member first elects to receive his benefit under subdivision (2) or (3) of subsection (a) of section 5-165 . In the event that income payments to a surviving beneficiary or contingent annuitant are payable under this subsection, such payments shall be in lieu of payments under subsections (a) and (b) of this section.