50/10 retirement joint and last-survivor option. -- A member may elect to receive a decreased retirement allowance during his lifetime and have the retirement allowance continued after his death to a contingent annuitant during the lifetime of such person. The retirement allowance pursuant to this option shall be determined as provided in subdivision A 5 of § 51.1-155 or subsection A of § 51.1-217, in accordance with the retirement plan covering such member, except (i) the present value of future retirement benefits shall be calculated based on the life expectancies of both the member and the contingent annuitant and (ii) the actuarially computed present value of the payments expected to be made under this option shall be actuarially equivalent to the actuarially computed present value of the payments expected to be made to the member as determined pursuant to subdivision A 5 of § 51.1-155 or subsection A of § 51.1-217, in accordance with the retirement plan covering such member.
For purposes of this subdivision, retirement shall be deemed to commence on the effective date of a member's service retirement or disability.
If such an election is made as a result of the death or divorce of the contingent annuitant, the benefit payable to the retired member may be adjusted retroactively for a period of not more than 60 days from the date the Board first receives notification of the desire of the retired member to make such a change.
Va. Code § 51.1-165