year. The MRA is based on the employee's birth year as shown on the table below: Immediate and Deferred Retirement For an immediate retirement (which starts the first day of the first full month after the employee separates from service) or a deferred retirement (which starts on a date of the employee's choosing) the employee must meet one of the following combinations of age and years of actual creditable service: Age 62 with 5 years, Age 60 with 20 years (but an employee retiring under this criterion is not eligible for deferred retirement), At least the MRA with 30 years, or At least the MRA with 10 years (but for employees under age 62 with less than 30 years, the benefit is permanently reduced by 5/12 of one percent for each month the employee is under age 62, unless the employee has at least 20 years' service and agrees to defer the annuity until age 62 or older). Other Retirement Options Employees facing either involuntary separation (for reasons other than misconduct), or voluntary separation in lieu of a "reduction in force" (similar to a layoff) can, in some cases, qualify for early retirement. The employee must either be age 50 with 20 years of actual creditable service, or have 25 years of actual creditable service at any age (the MRA does not apply in this case). Disability retirement is also a potential option for eligible federal employees with at least 18 months of service who no longer can perform their duties. The following conditions are required: the employee must have become disabled, while employed in a position subject to FERS, because of a disease or injury, for useful and efficient service in the employee's current position, the disability must be expected to last at least one year, and the agency must certify that it is unable to accommodate the disabling medical condition in the employee's present position and that it has considered the employee for any vacant position in the same agency at the same grade/pay level, within the same commuting area, for which the employee is qualified for reassignment. Annuity calculation The FERS annuity is based on a specified percentage (either 1% or 1.1% for most employees, see below), multiplied by (a) the length of an employee's Federal service eligible for FERS retirement (referred to as "creditable Federal service", which may not be the actual duration of Federal employment)