5 CFR §842.406

1. (a)The annuity of a congressional employee or Member who is first covered by FERS on or before December 31, 2012, and who has had at least 5 years of service as a congressional employee, Member, or any combination thereof totaling 5 years is—
   1. (1)One and seven-tenths percent of average pay multiplied by the total number of years of service as a Member and/or congressional employee not exceeding 20 years; plus
   2. (2)One percent of average pay multiplied by the years of service other than that of a Member and/or congressional employee.
2. (b)Except as provided in paragraph (c) of this section, the annuity of a congressional employee or Member who is first covered by FERS after December 31, 2012, or Member re-elected with less than 5 years of FERS service after December 31, 2012, and who has had at least 5 years of service as a congressional employee, Member, or any combination thereof totaling 5 years is 1 percent of average pay multiplied by total service.
3. (c)The annuity of a congressional employee or Member is 1.1 percent of average pay multiplied by total service, provided the congressional employee or Member—
   1. (1)Has completed 20 years of service; and
   2. (2)Is at least age 62 at the time of separation on which entitlement to an annuity is based.