The Thrift Savings Plan is essentially the federal government’s version of a 401(k). Both are defined contribution retirement accounts governed by the same IRS rules, with the same annual contribution limits, the same tax treatment options, and the same early withdrawal penalties. So if you’re asking whether the TSP is the same as a 401(k), the honest answer is: same category of account, different sponsor, and that difference in sponsorship changes how matching works, what you can invest in, and what you pay in fees.
Who Each Plan Covers
The TSP is open only to federal civilian employees and members of the uniformed services, including the Ready Reserve.1The Thrift Savings Plan (TSP). About the Thrift Savings Plan (TSP) If you work for a federal agency, the postal service, or any branch of the military, you’re eligible. New hires under the Federal Employees Retirement System are automatically enrolled at 3% of basic pay unless they opt out or change the amount.2U.S. Office of Personnel Management. FERS Information
401(k) plans are sponsored by private-sector and nonprofit employers. Eligibility rules vary by company, but federal law limits how restrictive they can be. A plan generally cannot require you to be older than 21 or to have more than one year of service before you start making your own contributions.3Internal Revenue Service. 401(k) Plan Qualification Requirements An employer can require up to two years of service before you become eligible for employer contributions, but only if you vest immediately once you qualify. These minimum standards come from ERISA.4U.S. Department of Labor. FAQs about Retirement Plans and ERISA
Contribution Limits Are the Same
The IRS sets one annual deferral ceiling that covers both plans. In 2026, you can contribute up to $24,500 in elective deferrals to either a TSP or a 401(k).5Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Participants 50 or older can add $8,000 in catch-up contributions for a personal ceiling of $32,500. A higher catch-up applies in a narrow band: participants aged 60 through 63 can defer an extra $11,250 in 2026, bringing their ceiling to $35,750.6IRS.gov. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living
Add employer contributions in and the total annual additions to your account cannot exceed $72,000 in 2026, not counting catch-up amounts.6IRS.gov. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living Both plans also let you split contributions between traditional (pre-tax) and Roth (after-tax), and both apply the 10% additional tax on withdrawals before age 59½ unless an exception fits.
Employer Matching Is Where the Plans Diverge
TSP matching follows a single, predictable formula for participants under FERS and the Blended Retirement System. The government contributes 1% of your basic pay automatically, whether or not you put anything in.7The Thrift Savings Plan (TSP). Contribution Types On top of that, it matches the first 3% you contribute dollar-for-dollar and the next 2% at 50 cents on the dollar. Contribute 5% of your pay, and the government adds a total of 5%. Contribute less, and you leave money behind.
Private 401(k) matching is whatever the employer decides. Some offer no match at all. Some use a safe harbor formula that mirrors the TSP’s structure. Some match 100% up to 6% or more. A few make a flat 3% nonelective contribution to every eligible employee whether that employee contributes or not.8Internal Revenue Service. Operating a 401(k) Plan You have to read your specific plan documents to know what you’re getting.
Investment Choices Look Very Different
The TSP is built to be simple. Five core index funds cover the major asset classes:9The Thrift Savings Plan (TSP). Individual Funds
- G Fund, government securities focused on capital preservation.
- F Fund, bonds tracking the Bloomberg U.S. Aggregate Bond Index.
- C Fund, large-cap U.S. stocks tracking the S&P 500.
- S Fund, small and mid-cap U.S. stocks tracking the Dow Jones U.S. Completion Total Stock Market Index.
- I Fund, international stocks tracking the MSCI ACWI IMI ex USA ex China ex Hong Kong Index.
Lifecycle (L) funds blend these five in proportions that shift from stocks toward bonds as you approach your target retirement date.10The Thrift Savings Plan (TSP). TSP Investment Options A mutual fund window is also available for access to thousands of additional funds, but it costs a $95 annual maintenance fee, a $37 annual administrative fee, and $28.75 per trade, plus each fund’s own expense ratio. You need at least $40,000 in your TSP account to use it, and no more than 25% of your balance can sit there at a time.11The Thrift Savings Plan (TSP). Mutual Fund Window
Private 401(k) menus vary enormously. A large employer might offer 30 to 40 institutional funds through Vanguard or Fidelity. A small business plan might offer a dozen. Some 401(k) platforms include a brokerage window that opens up nearly any publicly traded security. The quality of the menu depends on what the employer chose.
Fees Favor the TSP
Total expense ratios for the five core TSP funds range from 0.034% to 0.051%.12The Thrift Savings Plan (TSP). Expenses and Fees On a $100,000 balance, that’s about $34 to $51 a year. The plan covers millions of federal workers, and that scale keeps per-participant costs low.
Private 401(k) fees are all over the map. Large employers with billions in plan assets often negotiate institutional share classes with expense ratios below 0.10%, roughly comparable to the TSP. Small business plans are another matter. Between recordkeeping fees, advisory fees, and internal fund expenses that can run from 0.01% to well over 1.00%, a small-plan participant can pay ten to twenty times what a TSP participant pays. Compounded over a career, that gap matters.
Vesting Can Cost You If You Leave Early
Your own contributions are 100% yours immediately in both plans. Employer contributions are where the timing differs.
In the TSP, the agency’s automatic 1% contribution requires three years of federal civilian service to vest.13Office of Personnel Management (OPM). Federal Employees Retirement System – An Overview of Your Benefits Leave federal service before three years and you forfeit that 1% and its earnings. The matching contributions (the additional 4% when you contribute 5%) vest immediately.
Private 401(k) vesting varies more. Employer contributions must follow one of two allowable frameworks: cliff vesting, where you go from 0% to 100% after no more than three years, or graded vesting, where ownership builds gradually over up to six years.14Internal Revenue Service. Retirement Topics – Vesting Some employers vest immediately; many use the full allowable schedule. If a job change is on the horizon, check your vesting status. Walking away at two years and eleven months under a three-year cliff means losing every dollar of employer contributions.
Loans Have the Same Cap, Different Terms
Both plans allow borrowing from your own balance, up to 50% of your vested balance or $50,000, whichever is less.15Internal Revenue Service. Retirement Topics – Plan Loans
The TSP offers two loan types. A general purpose loan carries a 1-to-5-year repayment window with no documentation on the use of funds. A residential loan for buying a primary home stretches repayment to 15 years. The interest rate on both is the G Fund rate from the prior month, and the minimum loan is $1,000.16Thrift Savings Plan. Primary Residence General Purpose and Loans
Private 401(k) loans follow the same $50,000 cap but generally must be repaid within five years, with payments at least quarterly. A longer repayment period is allowed for loans used to buy a primary residence, and not every 401(k) plan permits loans at all.15Internal Revenue Service. Retirement Topics – Plan Loans Specific rates and fees are set by the plan sponsor.
One risk applies to both: if you leave your job with an outstanding loan, the unpaid balance can be treated as a distribution. That triggers income tax on the full amount and a possible 10% early withdrawal penalty if you’re under 59½. Rolling the outstanding amount into an IRA or another eligible plan by the tax filing deadline for that year avoids the hit.15Internal Revenue Service. Retirement Topics – Plan Loans
Early Withdrawals and the Rule of 55
Withdrawals before age 59½ from either plan generally trigger a 10% additional tax on top of regular income tax.17Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions Exceptions cover disability, certain medical expenses, and qualified domestic relations orders, among other situations.
The most useful exception in practice is the separation-from-service rule sometimes called the Rule of 55. Leave your job during or after the year you turn 55 and you can withdraw from that employer’s plan without the 10% penalty. The money is still taxed as ordinary income (unless it’s Roth), but the penalty falls away. This exception applies to 401(k) plans and the TSP, but not to IRAs. Rolling money into an IRA before age 59½ can cost you this flexibility.
Federal law enforcement officers, firefighters, customs and border protection officers, air traffic controllers, and certain other public safety employees get a better deal: the penalty-free separation age drops to 50. That applies whether the funds are in the TSP or a governmental defined contribution plan, and the exception extends to private-sector firefighters too.17Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions
You Can Move Money Between Them
Switching between federal and private employment doesn’t force you to abandon your retirement savings. After separating from federal service, you can roll a TSP balance into a 401(k), a traditional IRA, or another eligible retirement plan, provided the receiving plan agrees to accept it.18Thrift Savings Plan. Rollovers from the Thrift Savings Plan to Eligible Retirement Plans Roth TSP balances roll into a Roth account in another employer plan or into a Roth IRA.
Going the other way, the TSP accepts rollovers from 401(k), 403(b), traditional IRA, and SIMPLE IRA accounts into your traditional TSP balance. For Roth money, it accepts direct rollovers from Roth 401(k), Roth 403(b), and Roth 457(b) accounts, but not from a Roth IRA.19The Thrift Savings Plan (TSP). Move Money Into the TSP That last restriction catches some people who consolidated retirement money into a Roth IRA during a break between jobs. Unpaid loan balances, distributed excess deferrals, and certain life insurance cost amounts cannot be rolled over.