The federal Thrift Savings Plan (TSP) is the defined contribution retirement plan for civilian federal employees and uniformed-service members, and it works as the government’s version of a private-sector 401(k). Established by the Federal Employees’ Retirement System Act of 1986 and administered by the Federal Retirement Thrift Investment Board, it is the largest defined contribution plan in the world, holding roughly $963.3 billion for about 7.2 million participants as of December 31, 2024 (Source: FRTIB, 2025).
The federal Thrift Savings Plan is a payroll-funded retirement account for federal workers and service members that mirrors a 401(k). Eligible FERS employees receive agency contributions of up to 5%, invest in five core funds plus Lifecycle funds, and choose traditional (pre-tax) or Roth (after-tax) treatment. For 2026 the elective deferral limit is $24,500 (Source: IRS Notice 2025-67, 2025).
What is a Thrift Savings Plan, and how does it work?
The federal Thrift Savings Plan is a defined contribution retirement plan created by the Federal Employees’ Retirement System Act of 1986 (FERSA) and administered by the Federal Retirement Thrift Investment Board (FRTIB), an independent federal agency (Source: TSP.gov, About the TSP, 2026). Participants fund it through payroll deduction and invest in a small menu of funds, and the balance grows with contributions plus earnings.
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Because the TSP is a defined contribution plan, the payout is not a guaranteed pension amount (Source: TSP.gov, About the TSP, 2026). It is the largest defined contribution plan in the world, with about 7.2 million accounts and assets near $963.3 billion as of December 31, 2024 (Source: FRTIB, 2025).
Where the TSP fits in the federal retirement package
For employees under the Federal Employees’ Retirement System (FERS), the TSP is one of three parts of retirement income, alongside the FERS basic annuity (pension) and Social Security (Source: TSP.gov, About the TSP, 2026). The TSP is the portion the participant funds and directs, while the FERS annuity and Social Security operate as separate systems.
Coordinating a TSP with Social Security timing and future Roth conversions is where much of the retirement tax planning happens, a focus of the Q3 Advisors Roth conversion planning service.
Is a TSP the same as a 401(k)?
A TSP is not identical to a 401(k) but is the federal equivalent, sharing the same 2026 elective deferral limit of $24,500 under Internal Revenue Code section 402(g) (Source: IRS Notice 2025-67, 2025). Both are defined contribution plans funded by payroll deduction with employer or agency contributions. The main differences are the fund menu, the fee level, and the FERS match.
| Feature | Federal TSP | Private 401(k) |
|---|---|---|
| 2026 elective deferral limit | $24,500 (section 402(g)) | $24,500 (section 402(g)) |
| Who administers it | FRTIB, an independent federal agency | Private employer plus a plan provider |
| Investment menu | Five core funds plus Lifecycle funds | Varies by employer plan |
| Administrative costs | Very low (single digits in basis points) | Varies, often higher |
| Employer or agency match | Up to 5% for FERS (1% automatic plus 4%) | Set by each employer |
Who is eligible for a Thrift Savings Plan?
Eligibility for the federal Thrift Savings Plan is limited to federal government civilian employees and members of the uniformed services, including the Ready Reserve (Source: TSP.gov, About the TSP, 2026). Most FERS civilians and members under the Blended Retirement System participate. Private-sector civilians cannot open a TSP; the closest equivalents are employer 401(k) plans and individual retirement accounts (IRAs).
Newer federal hires are generally enrolled automatically; FERS civilian employees hired after October 1, 2020 are typically auto-enrolled at a 5% contribution rate (Source: TSP.gov, Contribution Types, 2026). Participants can change or stop contributions at any time.
How much does the government match in the TSP?
Under FERS, an eligible participant who contributes 5% of basic pay receives a total agency or service contribution of 5%: a 1% automatic contribution plus a 4% match (Source: TSP.gov, Contribution Types, 2026). The automatic 1% is paid each pay period regardless of whether the employee contributes anything.
On the first 5% the employee contributes, the first 3% is matched dollar for dollar and the next 2% at 50 cents on the dollar (Source: TSP.gov, Contribution Types, 2026). One nuance often missed: all agency automatic and matching contributions land in the traditional (pre-tax) balance, even for a participant who contributes only to Roth.
| Your contribution | Agency automatic | Agency match | Total added by agency |
|---|---|---|---|
| 0% | 1% | 0% | 1% |
| 3% | 1% | 3% | 4% |
| 5% | 1% | 4% | 5% |
Employees under the older Civil Service Retirement System (CSRS) may contribute to the TSP but receive no agency matching or automatic 1% contribution (Source: TSP.gov, Contribution Types, 2026).
Traditional vs. Roth TSP: the tax choice
The TSP offers two contribution tax treatments: traditional (pre-tax) and Roth (after-tax), and participants can use both at once (Source: TSP.gov, Contribution Types, 2026). Traditional contributions reduce current taxable income and are taxed on withdrawal, effectively a payroll tax deduction, while Roth contributions are after-tax with qualified withdrawals potentially tax-free.
| Feature | Traditional TSP | Roth TSP |
|---|---|---|
| Contribution tax treatment | Pre-tax (reduces current taxable income) | After-tax |
| Withdrawal tax treatment | Taxed as ordinary income | Qualified withdrawals may be tax-free |
| Agency and automatic match lands in | Traditional balance | Traditional balance (not Roth) |
| Lifetime RMDs | Apply at age 73 | Not required for years after 2023 |
As of January 28, 2026, the TSP added a Roth in-plan conversion feature, letting participants convert traditional balances to Roth through My Account without first rolling the money to an IRA (Source: TSP.gov, Contribution Types, 2026). A conversion is taxable as ordinary income in the year it is done and cannot be reversed, so timing matters. Q3 Advisors covers the mechanics in its guide to how much to convert to Roth and the 2026 Roth conversion deadline.
What are the five TSP funds?
The federal Thrift Savings Plan offers five core individual funds (G, F, C, S, and I) plus a series of Lifecycle (L) target-date funds (Source: TSP.gov, Investment Options, 2026). The individual funds cover government securities, bonds, and U.S. and international stocks, and each L Fund blends them into a mix that grows more conservative over time.
| Fund | What it holds |
|---|---|
| G Fund | U.S. Treasury securities specially issued to the TSP; principal and interest backed by the U.S. government |
| F Fund | Fixed income index tracking the Bloomberg U.S. Aggregate Bond Index |
| C Fund | Large-cap U.S. stock index tracking the S&P 500 |
| S Fund | Small-cap and mid-cap U.S. stock completion index |
| I Fund | International developed-markets stock index |
The Lifecycle (L) Funds are target-date options that shift from a higher stock allocation toward more conservative holdings as the target year approaches (Source: TSP.gov, Lifecycle Funds, 2026). A mutual fund window is also available for outside mutual funds, with extra fees and a 25% cap on the balance invested through it.
Low costs as a signature feature
Low administrative expenses are a defining trait of the federal Thrift Savings Plan. Net administrative expense ratios have historically run in the single digits of basis points, roughly a few cents per $1,000 of balance (Source: TSP.gov, Expenses and Fees, 2026). Per-fund figures change each year; tsp.gov shows the current numbers.
What are the TSP contribution limits for 2026?
For 2026, the TSP elective deferral limit is $24,500, up from $23,500 in 2025 (Source: IRS Notice 2025-67, 2025). The TSP shares this section 402(g) cap with 401(k), 403(b), and governmental 457 plans. Age-based catch-up amounts and a total additions limit apply on top of it.
| 2026 limit | Amount | Applies to |
|---|---|---|
| Elective deferral (402(g)) | $24,500 | Regular employee contributions |
| Age-50 catch-up (414(v)) | $8,000 | Participants age 50 and older |
| Super catch-up (ages 60 to 63) | $11,250 | Participants ages 60, 61, 62, 63 |
| Annual additions (415(c)) | $72,000 | Total contributions including agency match |
A SECURE 2.0 rule also changes how catch-up contributions are made. Participants whose prior-year FICA wages exceeded $150,000 are generally required to make catch-up contributions on a Roth (after-tax) basis rather than traditional. That interacts with later tax planning, including the net investment income tax; see the Q3 Advisors overview of the net investment income tax for 2026.
When can I withdraw from my TSP without penalty?
Withdrawals from a traditional TSP are generally taxed as ordinary income, and a 10% early-withdrawal penalty can apply before age 59.5 (Source: IRS, Retirement Topics, 2025). In-service withdrawals are generally available at age 59.5, and separating from federal service in or after the year you turn 55 (age 50 for certain public-safety roles) can allow penalty-free access earlier.
The TSP also permits loans (general-purpose and residential) and hardship withdrawals under specific conditions, each with its own rules and tax effects.
What happens to my TSP when I leave federal service?
After separating from federal service, a participant can generally keep the TSP account if the vested balance is $200 or more, leaving the money invested in TSP funds (Source: TSP.gov, 2026). Alternatively, the balance can often be rolled over into an IRA or another eligible employer plan.
Matching contributions vest immediately, while the FERS automatic 1% contribution generally vests after two to three years of service. A rollover to an IRA can open the door to staged Roth conversions, and many investors weigh the timing with a Roth conversion break-even analysis.
At what age are TSP required minimum distributions required?
Required minimum distributions (RMDs) from a traditional TSP generally begin at age 73 under the SECURE 2.0 Act (Source: IRS Publication 590-B, 2025). The first RMD is due by April 1 of the year after you turn 73, and later RMDs by December 31 each year. Those born in 1960 or later have an RMD age of 75, first applying in 2035.
Roth TSP balances are treated differently. Under SECURE 2.0 section 325, designated Roth accounts in employer plans, including the Roth TSP, are not subject to lifetime RMDs for tax years beginning after December 31, 2023 (Source: IRS RMD FAQs, 2025). See the Q3 Advisors guide on required minimum distributions for 2026.
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Q3 Advisors is a registered investment adviser focused on retirement tax planning. This page is educational and is not advice; consult a qualified professional.
Frequently asked questions
Is a TSP the same as a 401(k)?
A TSP is the federal equivalent of a 401(k), not an identical plan. Both are defined contribution plans funded by payroll deduction with employer or agency contributions, and both share the same 2026 elective deferral limit of $24,500 (Source: IRS Notice 2025-67, 2025). The TSP differs in its fund menu, its very low administrative costs, and its FERS matching structure.
Is TSP better than a 401(k)?
Whether a TSP or a 401(k) fits any individual depends on personal circumstances, so this is educational information rather than a recommendation. The TSP is known for very low administrative expenses and a simple fund menu, while 401(k) plans vary by employer in cost and investment choice (Source: TSP.gov, Expenses and Fees, 2026). Suitability can vary by goals, taxes, and risk tolerance.
Are TSP contributions tax deductible?
Traditional TSP contributions are made pre-tax through payroll deduction, so they reduce current taxable income much like a deduction, and the money is taxed later on withdrawal (Source: TSP.gov, Contribution Types, 2026). Roth TSP contributions are made with after-tax dollars and are not deductible, but qualified withdrawals may be tax-free. Participants can use both treatments at the same time.
Can civilians open a Thrift Savings Plan?
Private-sector civilians cannot open a TSP. Eligibility is limited to federal government civilian employees and members of the uniformed services, including the Ready Reserve (Source: TSP.gov, About the TSP, 2026). People outside federal service generally use employer 401(k) plans and individual retirement accounts (IRAs) as comparable retirement savings vehicles instead.
How much does the government match in a TSP?
Under FERS, an eligible participant who contributes at least 5% of basic pay receives a total of 5% from the agency: a 1% automatic contribution plus a 4% match (Source: TSP.gov, Contribution Types, 2026). The first 3% is matched dollar for dollar and the next 2% at 50 cents on the dollar. All agency contributions land in the traditional balance.
What are the 5 TSP funds?
The five core individual TSP funds are the G Fund (U.S. Treasury securities backed by the government), the F Fund (bond index), the C Fund (large-cap U.S. stock index), the S Fund (small-cap and mid-cap U.S. stock index), and the I Fund (international stock index) (Source: TSP.gov, Investment Options, 2026). Lifecycle (L) target-date funds blend these five.
