11 Del. C. § 8374: Withdrawal benefit.

(a) The accumulated contributions with interest of a member who is neither eligible for a service nor disability pension, nor has a vested right to a service pension, shall be refunded upon withdrawal from service. There shall be a rebuttable presumption that a former member who fails to apply for a withdrawal benefit within 5 years after the date of withdrawal has waived the right to such benefit.

(b) If a member has a vested right to a service pension and withdraws from service and is not immediately eligible for a service or disability benefit, the member may request refund of accumulated contributions with interest. Refund of such contributions shall extinguish all rights to benefits under this subchapter.