Key Takeaways
- Creditable service rules vary for FERS, CSRS, and military time, affecting both eligibility and retirement calculations.
- Recent changes and specific types of service or leave require careful review to ensure your pension reflects your full federal career.
Did you know that even a few months of uncredited federal or military service can significantly change your retirement eligibility and benefit calculation? Understanding what counts—and what does not—under FERS, CSRS, and former military service is essential as you plan your retirement journey.
What Is Creditable Service?
Understanding the term
Creditable service refers to the periods of your federal civilian employment—and, in many cases, military service—that the U.S. government officially recognizes for retirement eligibility and pension calculations. It determines both when you can retire and the size of your eventual annuity.
Applicable federal retirement systems
Three major federal retirement systems use the creditable service concept:
- Federal Employees Retirement System (FERS)
- Civil Service Retirement System (CSRS)
- Military retirement systems (for blending or transfer considerations)
Each system has its own rules for what service counts and how.
Why Does Creditable Service Matter?
Impact on retirement eligibility
The number of years and months you accumulate as creditable service directly affects when you become eligible to retire under FERS or CSRS. For example, FERS requires the minimum retirement age plus at least five years of creditable civilian service, while CSRS typically requires at least five years of civilian service as well.
Effect on benefit calculations
Your total creditable service determines your pension’s calculation. More years of service generally result in a higher annuity since the retirement formula multiplies your service years by a percentage of your high-3 average salary.
Which Service Counts Toward FERS and CSRS?
Civilian federal employment types
The following typically count as creditable service:
- Permanent, full-time federal employment
- Part-time, seasonal, or intermittent service (although part-time is prorated)
- Prior federal employment periods if you left and later rehired, when certain conditions are met
- Time spent in a congressional or legislative staff position
Temporary or non-career appointments may be subject to different rules, especially for FERS.
Military service and deposits
Most active duty military service counts as creditable service—but under both FERS and CSRS, you are usually required to make a deposit for post-1956 military time to include it in your civilian annuity calculation.
Breaks in service and re-hires
If you leave federal service and return, your eligibility to include previous service as creditable depends on repayment of any retirement refunds and meeting re-hire requirements. These processes can be complex and sometimes require detailed record reviews.
How Is Military Service Credited?
Rules for active duty time
Active duty service in the U.S. Armed Forces (Army, Navy, Air Force, Marine Corps, Coast Guard, and commissioned corps of the Public Health Service and NOAA) generally counts for retirement, provided you receive an honorable discharge. However, the specific rules depend on when the service occurred and if you are also eligible for a military pension.
Making military service deposits
For both FERS and CSRS employees, post-1956 military service must be “bought back” through a deposit, typically equal to a percentage of your military earnings. Failing to pay this deposit by the deadline often means this service will not be included in your retirement calculation, unless you do not qualify for Social Security upon retirement.
Special considerations since 2026
Since legislative changes in recent years, some nuances affect how military service is credited:
- The process and timeline for making deposits are now more clearly defined by OPM guidance.
- The repeal of the Windfall Elimination Provision in 2025 no longer reduces federal annuities for those who also receive Social Security.
Review any new documentation requirements for separations or retirements occurring in 2026 and beyond.
What Types of Leave Are Credited?
Sick leave
For FERS and CSRS participants, unused sick leave at retirement is converted to creditable service. You can’t use it to reach eligibility, but it can increase your annuity calculation. The conversion is based on a precise table issued by the Office of Personnel Management (OPM).
Annual leave
Unused annual leave is not counted as creditable service; instead, you are typically paid for it in a lump-sum payment when you separate or retire.
Unpaid leave and LWOP
Leave Without Pay (LWOP) can typically be credited for up to six months per calendar year. Beyond that, the excess LWOP is generally not counted toward your retirement.
Are There Service Types That Do Not Count?
Temporary appointments
Temporary federal appointments (sometimes referred to as “not-to-exceed” or seasonal, less than 1 year) are not automatically creditable, especially for service prior to certain rule changes. In some cases, you can make deposits to include temporary service, but this varies.
Volunteer and non-qualifying service
Volunteer work, internships not paid by federal appropriations, and other non-appointed roles do not count as creditable service for retirement.
Common Creditable Service Questions in 2026
Recent changes to federal policy
Federal retirement policy evolves. The repeal of the Windfall Elimination Provision, clarified deposit deadlines, and adjustments to record-keeping processes since 2025 have impacted how employees approach creditable service. Always review current OPM guidance for the most up-to-date criteria.
Scenarios and exceptions
Employees with complex service histories—such as breaks in service, military retirements, or transfers across agencies—should especially verify records, as exceptions may apply and new policies can change how service is credited or what documentation is required.
Key Considerations Before You Retire
Reviewing your service record
Carefully review your Official Personnel Folder (OPF) and any associated military or civilian records. Make sure all periods of federal or military service are fully documented, and check for gaps or missing time that might affect eligibility or calculation.
Correcting service credit issues
If you identify potential issues—such as missing service periods or unpaid deposits—contact your agency’s human resources office promptly for instructions on corrections as outlined by OPM processes. Addressing discrepancies before you submit retirement paperwork can help ensure your annuity is calculated accurately.
