Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 881.410. Vesting

(a) Provisions for vesting may be included in the contract between the municipality and the board.  When such provision is made it shall mean that a contributor who terminates his employment with the municipality after a stipulated age or length of service, or both, may, if he so elects in writing, leave his contributions, plus interest, as credited to his account, in the fund, and, upon reaching superannuation retirement age, receive a superannuation retirement allowance and accumulated deductions would include interest from date of termination until the earlier of the date of commencement of the annuity or the date of payment of member contributions.

(b) Upon the termination of the retirement plan, all members, regardless of credited service, shall be deemed fully vested in their accrued benefit to the extent the benefits provided under the plan are funded as of the date of termination.