FERS and the TSP are not the same thing. The Federal Employees Retirement System (FERS) is the overall retirement program for most civilian federal workers, and the Thrift Savings Plan (TSP) is one savings account that sits inside it. They show up together on pay stubs and in HR paperwork, which is why the two get blurred, but they operate under different rules, are funded differently, and pay out differently.
How the Two Fit Together
Congress created FERS through the Federal Employees’ Retirement System Act of 1986 as the retirement framework for civilian federal employees hired after 1983.1Office of the Law Revision Counsel. 5 U.S.C. Chapter 84 – Federal Employees Retirement System FERS is the umbrella. It sets the eligibility rules, benefit formulas, and administrative structure for the whole retirement package.
The TSP is one piece under that umbrella. It is governed by Sections 8431 through 8440f of the same chapter and functions as a tax-advantaged account employees use to invest for retirement.1Office of the Law Revision Counsel. 5 U.S.C. Chapter 84 – Federal Employees Retirement System It is not a separate retirement system. The Office of Personnel Management administers FERS overall; the Federal Retirement Thrift Investment Board runs the TSP.
The Three Parts of FERS
FERS is built on three separate income sources. Each does a different job.
- The FERS basic annuity, a traditional pension that pays a guaranteed monthly amount for life based on your salary and years of service.
- Social Security, which federal employees pay into through payroll taxes and can collect starting as early as age 62.
- The Thrift Savings Plan, a personal retirement savings account similar to a private-sector 401(k), where your balance depends on your contributions and investment performance.
So the TSP is one leg of FERS, not the whole thing. When people ask whether FERS and TSP are the same, this is the clearest answer: the TSP is inside FERS, alongside the pension and Social Security.
Guaranteed Pension vs. Investment Account
The basic annuity is a defined benefit. The government guarantees a specific monthly payment for life, calculated from your “high-3” average salary and your years of creditable service. The multiplier is 1 percent per year of service for most retirees, or 1.1 percent if you retire at age 62 or later with at least 20 years.2U.S. Office of Personnel Management. Computation Market conditions do not affect what lands in your account.
The TSP is a defined contribution plan. There is no guaranteed monthly amount. Your retirement income from the TSP depends on how much you put in, how much your agency puts in, and how your investments do. You pick from five individual funds — the G, F, C, S, and I Funds — or Lifecycle (L) Funds that blend them for a target retirement date.3The Thrift Savings Plan (TSP). TSP Investment Options
You also choose the tax treatment of your own contributions. Traditional contributions go in before taxes and are taxed when you withdraw. Roth contributions go in after taxes, and qualified withdrawals — including earnings — come out tax-free.4The Thrift Savings Plan (TSP). Traditional and Roth TSP Contributions Agency contributions always go into the traditional balance, whichever option you pick.
How Each Is Funded
The two are funded through entirely different mechanisms, which is another sign they are not the same benefit.
Basic Annuity
Your contribution to the basic annuity is mandatory and depends on when you were hired:5Congressional Budget Office. Increase Federal Civilian Employees Contributions to the Federal Employees Retirement System
- Hired before 2013: 0.8 percent of basic pay.
- Hired in 2013 (FERS-RAE): 3.1 percent of basic pay.6Office of Personnel Management. Benefits Administration Letter Number 13-102
- Hired in 2014 or later (FERS-FRAE): 4.4 percent of basic pay.5Congressional Budget Office. Increase Federal Civilian Employees Contributions to the Federal Employees Retirement System
Deductions come out of every paycheck automatically. Your agency contributes a larger share on top of that. All of it goes into the Civil Service Retirement and Disability Fund, which pays out benefits under both the older CSRS system and current FERS.7Office of the Law Revision Counsel. 5 U.S.C. 8348 – Civil Service Retirement and Disability Fund
TSP
TSP contributions from you are voluntary, but your agency puts money in either way. Every FERS employee receives an automatic agency contribution equal to 1 percent of basic pay, even if you contribute nothing. When you do contribute, the agency matches dollar-for-dollar on the first 3 percent of pay and 50 cents on the dollar for the next 2 percent.8Office of the Law Revision Counsel. 5 U.S.C. 8432 – Contributions Contributing at least 5 percent of your salary captures the full match.
For 2026, the annual employee contribution limit is $24,500. If you are 50 or older during the year, you can add $8,000 in catch-up contributions. Employees turning 60, 61, 62, or 63 in 2026 qualify for a higher catch-up limit of $11,250.9The Thrift Savings Plan (TSP). 2026 TSP Contribution Limits
Vesting
Vesting rules are also different. The basic annuity requires five years of creditable civilian service before you own a future pension; leave earlier and you can only get your own contributions back. In the TSP, your own contributions and agency matching contributions are yours immediately. The agency’s automatic 1 percent contribution requires three years of service to vest (two years for certain designated positions).10Thrift Savings Plan (TSP). Thrift Savings Plan Vesting Requirements and the TSP Service Computation Date
When You Can Collect
You can start collecting the FERS basic annuity when you meet one of these age-and-service combinations:11U.S. Office of Personnel Management. Eligibility
- Age 62 with 5 years of service.
- Age 60 with 20 years of service.
- Minimum Retirement Age (MRA) with 30 years of service.
- MRA with 10 years, with a 5 percent reduction for each year you are under 62 unless you delay collecting.
Your MRA depends on birth year. For employees born in 1970 or later, it is 57.11U.S. Office of Personnel Management. Eligibility
The TSP has no separate retirement eligibility test. You can access your balance once you separate from federal service at any age. Withdrawing before 59½ generally triggers a 10 percent early withdrawal penalty on top of income tax, but if you separate during or after the year you turn 55, the penalty does not apply.12Thrift Savings Plan (TSP). Early Withdrawal Penalty Tax
Annual cost-of-living adjustments apply to FERS annuities, but generally only after age 62 for regular retirees. The 2026 FERS COLA is 2.0 percent.13U.S. Office of Personnel Management. Learn More About Cost-of-Living Adjustments (COLA) The TSP has no COLA; your balance simply grows or shrinks with the markets.
What Happens at Death
The two also treat death benefits differently, and the elections you make matter.
At retirement, you can elect a FERS survivor annuity that continues a portion of your pension to your spouse. A full survivor annuity pays 50 percent of your unreduced annuity; a partial one pays 25 percent.14U.S. Office of Personnel Management. How Is the Amount of My Benefits as a Surviving Spouse Determined Your own annuity is reduced by 10 percent for a full survivor benefit or 5 percent for a partial one.15U.S. Office of Personnel Management. How Is the Reduction Calculated If you are married, a full survivor annuity is the default, and choosing less requires your spouse’s written consent.
The TSP handles death through beneficiary designations. A surviving spouse gets a beneficiary participant account in their own name and can keep the money in the TSP. A non-spouse beneficiary cannot keep a TSP account; the balance is paid out or rolled into an inherited IRA.16The Thrift Savings Plan (TSP). Beneficiary Distributions The TSP follows its own beneficiary form, not your will, so keeping the designation current matters.
Tax Treatment
Both are subject to federal income tax, but the details are not identical.
FERS annuity payments are partially taxable. A small portion of each check is treated as a tax-free return of the contributions you already paid in, and the rest is taxed as ordinary income. OPM sends a Form CSA 1099-R each year showing the payments and any tax withheld.17Internal Revenue Service. Tax Guide to U.S. Civil Service Retirement Benefits
Traditional TSP withdrawals are fully taxed as ordinary income when you take them. Qualified Roth TSP withdrawals, including earnings, are tax-free if your Roth balance has been open for at least five years and you are 59½ or older.4The Thrift Savings Plan (TSP). Traditional and Roth TSP Contributions State tax treatment varies; some states fully exempt federal pensions, some partially, and some tax them like any other income.
Put together, FERS is the retirement program you belong to, and the TSP is one of the accounts that program provides. Understanding which is which is what tells you how much guaranteed income you will have, how much is riding on your own contributions, and what choices you need to make before you retire.