By law, the dollar amount of a CSRS annuity cannot exceed 80 percent of your high-3 average salary. That’s the amount you would get if you had 41 years and 11 months of creditable service.
When you have reached that point, retirement contributions will continue to be taken out of your salary. However, at retirement, those excess contributions will be returned to you with interest, which is currently 3 percent per year. OPM will also offer you an opportunity to buy an additional retirement annuity with that refunded money.
The 80 percent limit does not apply to additional annuity purchased with excess contributions or through the Voluntary Contributions Program, COLAs, or as a result of additional retirement credit given for unused sick leave.
There is no annuity limit under FERS.