(a) For employees who entered on duty on or before June 30, 1997, and whose military service was performed prior to that date, credit for military service is included in Federal Benefit Payments under the terms and conditions applicable to each plan.
(b) For employees who enter on duty after June 30, 1997, military service is not creditable toward Federal Benefit Payments, even if performed as of June 30, 1997.
(c) For employees who entered on duty on or before June 30, 1997, but who perform military service after that date, the credit for military service is not included in Federal Benefit Payments.