This is the time of year when many federal workers start planning for retirement at the end of the year. But many feds are confused about when they can retire and what kind of monthly check they can expect.

Except in cases of disability, or where an employe's job is abolished, workers who wish to retire on immediate annuity must be age 55 with at least 30 years' service, or age 60 with 20 years' service, or age 62 with five years' service. Pensions are based on length of service and are figured as a percentage of the highest three-year salary average. Unused sick leave can be credited toward service time for retirement purposes, as can military service time.

An employe retiring with five years' service, for example, gets an annuity equal to 7 1/2 percent of his or her highest three-year salary average. An employe with 10 years gets an annuity equal to 16.25 percent of the high-three; a 20-year worker gets 26.25 percent; a 25-year employe gets 45.25 percent; the 30-year worker gets 56.25 percent and an employe with 42 years gets 80 percent of the high-three average salary as pension.