TSP Roth conversion: how to convert your TSP to Roth as a federal employee or retiree

Log in to My Account on tsp.gov and request a Roth in-plan conversion. The TSP moves the amount you choose from your traditional balance to your Roth balance. If you don't have a Roth balance yet, your first conversion creates one.

The amount you convert is taxable income for that year. The TSP will report it to you and the IRS on Form 1099-R. The TSP can't withhold tax on a conversion, so you pay it yourself. You usually do that through estimated tax payments or extra withholding from your pension.

• Each request must be at least $500, and you need a vested balance of at least $500.
• You can do up to 26 conversions in a calendar year.
• If you have money in the mutual fund window, you must move it to a core TSP fund before you can convert it.
• Your conversions come out of your traditional sources in proportion: your own contributions, agency automatic (1%) and matching contributions, and rollovers. Tax-exempt combat zone money goes along in the same proportion.
• If you are married, you don't need your spouse's consent.
• Non-spouse beneficiaries can't convert.

Both work. Converting inside the TSP keeps your money in the plan you already know. It keeps the age-55 penalty rule (below), and it takes a few clicks. Rolling to an IRA first gives you more investment choices and lets you convert from specific holdings.

If you are under 59½, the biggest difference is the early withdrawal rule. Your TSP money stays penalty-free if you left federal service in or after the year you turned 55. For law enforcement, firefighters, air traffic controllers and other public safety employees, the age is 50. Roll it to an IRA and that protection is gone. For more on rolling plans to IRAs, see 401(k) to Roth IRA.

Your FERS pension is 1% of your high-3 average salary for each year of service. It is 1.1% if you retire at 62 or later with at least 20 years. It is taxable income, and it comes first when you count your bracket room.

You get the FERS supplement if you retire on an immediate annuity before 62. Examples are retiring at your MRA with 30 years, or at 60 with 20 years. It stops at 62. It is also taxable. So a $33,000 pension plus an $18,000 supplement means $51,000 of income before any conversion.

The supplement has an earnings test. Say you work after retiring and earn more than Social Security's limit ($24,480 in 2026). Then your supplement shrinks by $1 for every $2 over. The test looks at pay from work. TSP withdrawals and Roth conversions are not earnings from work, so converting won't reduce your supplement.

Your MRA (minimum retirement age) is 56 if you were born 1953 to 1964. It rises by two months a year, to 57 if you were born in 1970 or later. If you retire at your MRA with 30 years, you get an unreduced pension plus the supplement.

If you retire at your MRA, you are likely under 59½. That matters for conversions in two ways. First, pay the tax from your savings, since there is no withholding option. Second, each conversion has its own five-year clock. If you take out converted money within five years and before 59½, you can owe the 10% penalty. So plan to leave your converted money alone. See The 5-year rules.

Your FEHB premium does not depend on your income, so a conversion doesn't change it. Medicare is different. Your Part B and Part D premiums go up when your income from two years earlier is above certain levels. For 2026, the first surcharge starts above $109,000 for single filers and $218,000 for joint filers.

Many federal retirees keep FEHB and add Medicare Part B at 65. If you plan to do that, your conversions at 63 and later count toward those premiums. Conversions before 63 do not. Check the tiers at 2026 IRMAA brackets and checker.