(1) An inactive vested member may purchase any service for which the member is eligible any time prior to retirement.

(2) The inactive vested member's most recent termination date will be considered the purchase request date for all service purchases other than refunded service, which is addressed in 19-2-603, MCA.

(a) The actuarial cost of the service purchase will be determined based on the member's age at the time of the purchase and the member's salary at the time of the member's most recent termination.

(b) Interest, compounded monthly, will be charged from the member's most recent termination date to when the member completes payment for the cost of the purchase:

(i) for members terminated prior to July 1, 2010, at an effective annual rate of 8% per year; and

(ii) for members terminated on or after July 1, 2010, at an effective annual rate of 7.75% per year.

(3) An inactive vested member who purchases service may not elect a retirement date prior to the date the service purchase is completed.