Thrift Savings Plan (TSP)

The Thrift Savings Plan is a defined contribution retirement plan created by Congress for employees of the federal government, including uniformed servicemembers. It functions as the federal government's equivalent of a private-sector 401(k): contributions come from payroll, grow with a tax advantage, and the balance belongs to the employee, subject to the plan's own withdrawal and rollover rules. Its defining characteristics are a small, low-cost fund lineup and, for most federal civilian employees, contributions from the government itself that don't depend on the employee contributing anything at all.

Federal employees covered by the Federal Employees Retirement System (FERS) generally receive an automatic 1% agency contribution to their TSP regardless of whether they contribute anything themselves, plus a dollar-for-dollar match on the first 3% of pay they defer and a 50-cent match on the next 2% — a combined match of up to 4% on top of the automatic 1%, for a total of up to 5% in agency money if the employee defers at least 5%. Members of the uniformed services under the Blended Retirement System receive a similar structure. Employees still under the older Civil Service Retirement System (CSRS), a shrinking population, can contribute to the TSP but don't receive matching agency contributions, since CSRS already provides a traditional pension.

The investment lineup is intentionally narrow compared with most 401(k)s: the G Fund (government securities, effectively principal-protected), F Fund (a fixed-income index), C Fund (a large-cap U.S. stock index roughly tracking the S&P 500), S Fund (a small- and mid-cap U.S. stock index), and I Fund (an international stock index) — plus a series of L (Lifecycle) funds that blend the five core funds into a single target-date-style allocation that shifts more conservative as the target date approaches. The tradeoff for the limited menu is unusually low expense ratios, historically among the cheapest in the retirement-plan industry.

Employee deferral limits track the private-sector figures: $24,500, with an $8,000 catch-up starting at age 50 and a temporary "super" catch-up of $11,250 for those aged 60 through 63. Both traditional and Roth TSP contributions are available, with the same tax mechanics as a 401(k)'s traditional and Roth options. When a federal career ends, the balance can stay in the TSP, roll to an IRA, or roll to a new employer's plan, similar to a private-sector 401(k) rollover.

A hypothetical example: Captain Alvarez, a federal civilian employee under FERS earning $90,000, defers 5% of pay — $4,500 — into her TSP for the year, split between the C Fund and the I Fund. Her agency automatically adds 1% ($900) regardless of her own contribution, plus a match on her 5% deferral: dollar-for-dollar on the first 3% ($2,700) and 50 cents on the dollar on the next 2% ($900). Her total agency contribution for the year is $4,500, on top of her own $4,500 — doubling her savings rate without her deferring an extra cent.

If she had contributed only 2% instead of 5%, she still would have received the automatic 1% but would have missed most of the available match, effectively forfeiting agency money she was entitled to.

Pros

• Automatic 1% agency contribution for most FERS employees, plus matching, on top of their own savings.
• Among the lowest-cost fund lineups of any employer retirement plan.
• Same high contribution limits as a 401(k), well above an IRA alone.
• Traditional and Roth options, same as a 401(k), let participants choose when to pay tax.

Cons

• The narrow fund menu offers little flexibility if you want exposure beyond the five core index funds and the L Funds, such as specific sector or actively managed strategies.
• Employees under the older CSRS system don't receive matching contributions.
• Withdrawal and loan rules have their own quirks distinct from private-sector 401(k) plans, so TSP-specific guidance matters more than generic 401(k) advice.
• Early withdrawals before 59 1/2 generally face the same 10% penalty and income tax that apply to a 401(k), with a narrower set of exceptions.