CSRS and FERS are both federal retirement systems, but they were designed in different eras and combine their parts differently. Understanding the contrast helps explain why two colleagues with similar careers can have very different retirement profiles.
Side-by-Side Overview
| Feature | CSRS | FERS |
|---|---|---|
| Typical hire period | Generally before 1984 | Generally 1987 or later (1984 to 1986 had special rules) |
| Main benefit | Pension annuity | Basic annuity, Social Security, and TSP |
| Annuity percentage | Higher per year of service (commonly 1.5 to 2 percent) | Generally 1 percent per year, or 1.1 percent in certain cases |
| Social Security | Generally not part of federal service coverage | Included, with its own benefits |
| Savings plan | TSP available, but not the main structure | TSP is a core component with agency contributions |
Why the Annuity Formulas Differ
CSRS was built so the pension carried most of the retirement income. Its annuity percentages are higher, which reflects that design. FERS spreads retirement income across three parts, so its basic annuity percentage is lower and the other components make up the difference.
What Changes for Real Decisions
The two systems affect how you think about retiring early, how much you rely on savings, and how Social Security fits into your income. Someone under FERS may need to evaluate TSP balances and Social Security timing. Someone under CSRS may focus more on the annuity formula and survivor options.
Where to Go Next
Read the FERS Guide or the CSRS Guide for more detail on each system.
The Same Career Under Each System
To see how the two systems differ, consider an employee with 30 years of service and a high-3 average salary of $90,000. Under CSRS, the standard formula gives 56.25 percent of the high-3, which is $50,625 per year. Under FERS, the basic annuity is 1 percent per year of service, which is $27,000 per year, or $29,700 if the 1.1 percent multiplier applies (age 62 or older with at least 20 years of service).
On its own, the FERS number looks much smaller. But a FERS employee also earns Social Security benefits and has a TSP account with agency contributions. Judging the systems fairly means comparing total retirement income, not the basic annuity alone. The examples are illustrative and use simplified assumptions.
Retirement Age and Service Rules
The general milestones are similar but not identical. CSRS commonly references age 55 with 30 years, age 60 with 20 years, and age 62 with 5 years. FERS uses the minimum retirement age (55 to 57, depending on birth year) with 30 years, age 60 with 20 years, and age 62 with 5 years, and also offers a reduced option at the MRA with 10 years of service. See our FERS eligibility article for details.
Cost-of-Living Adjustments
CSRS retirees generally receive an annual adjustment that follows the increase in consumer prices. FERS retirees generally receive adjustments that are capped relative to inflation when inflation is high, and in most cases they begin at age 62. Over a long retirement, this difference can add up.
Survivor Benefits and Insurance
Both systems allow a survivor annuity for an eligible spouse, and both reduce the retiree’s own annuity to pay for it. Health and life insurance continuation depends on enrollment history in either system, not on whether you are under CSRS or FERS.
Frequently Asked Questions
Which system is better?
Neither is better in every case. CSRS generally pays a larger basic annuity, and FERS provides a smaller annuity plus Social Security and TSP income. Which one is stronger for a given person depends on career length, TSP savings, Social Security timing and other factors.
Can I choose between CSRS and FERS?
Your coverage generally depends on when you were hired and on any past elections. Some CSRS employees were allowed to switch to FERS during past transfer periods, but you should not assume you can choose now. Ask your human resources office about your own situation.
What about employees hired in 1984 to 1986?
Rules for these years were different, and some employees were covered by CSRS Offset or moved to FERS. Confirm your category on your personnel records.
Where can I see my own category?
Your personnel actions list your retirement plan, and your human resources office can explain it.