24 Pa. C.S. § 8325
In the event that a member terminates school service or a multiple service member who is an active member of the State Employees' Retirement System terminates State service before any agreed upon payments , including USERRA leave, or return of benefits on account of returning to school service or entering State service and electing multiple service have been completed, the member or multiple service member who is an active member of the State Employees' Retirement System shall have the right to pay within 30 days of termination of school service or State service the balance due, including interest, in a lump sum, and the annuity shall be calculated including full credit for the previous school service, creditable nonschool service, or full-coverage membership. In the event a member does not pay the balance due within 30 days of termination of school service or in the event a member dies in school service or within 30 days of termination of school service or in the case of a multiple service member who is an active member of the State Employees' Retirement System does not pay the balance due within 30 days of termination of State service or dies in State service or within 30 days of termination of State service and before the agreed upon payments have been completed, the present value of the benefit otherwise payable shall be reduced by the balance due, including interest, and the benefit payable shall be calculated as the actuarial equivalent of such reduced present value.
24 Pa.C.S. § 8325