The basic CSRS annuity is expressed as a percentage of your high-3 average

salary. 

Your high 3 percentage is determined by a three-part formula based on

your length of creditable service. You earn:

• 1.5% x High-3 x first five years of service

• plus 1.75% x High-3 x next five years of service

• plus 2.0% x High-3 x all years of service over 10

Thus, after 10 years of service you have earned 16.25% of your "high three"

and after 30 years you have earned 56.25% (16.25% + 2% x 20 = 56.25%). 

By law, the percentage is limited to 80% (reached after 41 years and 11

months of service)however, unused sick leave can

be used in the formula to produce a greater result.

Your unused sick leave is converted into

months and days and added to your other service. Credit is given for whole

months only, (30 days). However, the time representing days of unused sick leave

is not counted toward your "high 3" years average salary or for establishing

eligibility for retirement.

Example 1:
Age	55
High-3	$60,000
Years of Service	30 years
.015 x 5 x $60,000	= $4,500
.0175 x 5 x $60,000	= $5.250
.02 x 20 x $60,000	= $24,000
	$33,750  (56.25% of High-3)

Example 2:
Age	60
High-3	$50,000
Years of Service	20 years
.015 x 5 x $50,000	= $3,750
.0175 x 5 x $50,000	= $4,375
.02 x 10 x $50,000	= $10,000
	$18,125  (36.25% of High-3)

Source: OPM RI 83-7