The annuity of an employee whose service includes part-time service is computed in accordance with § 842.403 , using the average pay based on the annual rate of basic pay for full-time service. This amount is then multiplied by the proration factor. The result is the annual rate of annuity before reductions for retirement before age 62, survivor benefits, or the reduction for an alternative form of annuity required by § 842.706 .
5 C.F.R. §842.407