Federal employees retiring before age 62 under the Federal Employees Retirement System (FERS) can use the FERS Annuity Supplement Calculator to estimate their Special Retirement Supplement (SRS). This benefit bridges the gap until Social Security begins. The Special Retirement Supplement provides temporary monthly payments based on the retiree’s expected Social Security benefit at ... https://www.federalpensionadvisors.com/fers-supplement-calculator