The Civil Service Retirement System (CSRS) was closed to new employees in 1984, but thousands of federal employees who started before 1984 are still under CSRS or CSRS-Offset today. If you have colleagues or supervisors nearing retirement, you may be wondering how their retirement compares to yours under FERS.
Quick Overview
| Feature | FERS | CSRS |
|---|---|---|
| Available to | Hired after Dec 31, 1983 | Hired before Jan 1, 1984 |
| Pension multiplier | 1% or 1.1% per year | 1.5–2.0% per year (varies) |
| Social Security | Yes — full participation | No (CSRS); partial (CSRS-Offset) |
| TSP matching | Up to 5% government match | No automatic match |
| COLA | CPI − 1 point (above 2%) | Full CPI |
| Employee contribution | 0.8–4.4% of pay | 7% of pay |
Pension Formula Comparison
FERS: High-3 × Years × 1% (or 1.1% at 62+/20+ years)
CSRS: Uses a tiered formula — 1.5% for the first 5 years of service, 1.75% for years 6–10, and 2.0% for years 11+.
For a 30-year career: CSRS yields approximately 56.25%, while FERS yields 30% (at 1%). However, CSRS employees contribute 7% of their salary vs. 0.8% for FERS.
Social Security: The Major Difference
CSRS employees generally did not pay into Social Security and are NOT eligible to collect it based on their federal service. FERS employees pay full FICA taxes and collect full Social Security benefits.
This means FERS employees have a significantly more diversified retirement income, while CSRS employees rely almost entirely on their (larger) pension.
CSRS-Offset is a hybrid — employees who left and returned to federal service, some under CSRS rules but with Social Security also applied. Their CSRS pension is reduced (“offset”) by the Social Security amount at 62.
COLA Comparison
This is where CSRS really stands out. CSRS retirees receive full CPI-based COLA every year. FERS retirees receive CPI minus 1 percentage point (if CPI > 2%), and NO COLA before age 62.
In a 5% inflation year:
- CSRS retiree: pension increases 5%
- FERS retiree (under 62): no increase
- FERS retiree (62+): pension increases 4%
Over a long retirement, this difference compounds substantially.
TSP Matching
FERS employees get up to 5% government TSP matching — a major advantage. CSRS employees receive no automatic agency matching.
Who Is Still Under CSRS?
In 2025, very few active employees remain under CSRS — they would need to have been hired before 1984 and be at least in their mid-50s. Most CSRS employees have now retired. However, some CSRS-Offset employees are still working.
The Bottom Line
CSRS offers a more generous pension formula and full COLA but no Social Security and no TSP match. FERS provides a more diversified income with Social Security, TSP matching, and a simpler pension — at a lower contribution rate. Neither is strictly “better” — they reflect different design philosophies.
For FERS employees, the key is to optimize all three pillars: maximize the pension through High-3 and years of service, collect full Social Security, and grow the TSP aggressively.