TSP Required Minimum Distribution (RMD) Calculator

Estimate your annual RMD from your Thrift Savings Plan, see how your traditional TSP balance depletes over time, and spot potential IRMAA surcharge triggers before they hit.

When does your TSP RMD start?

SECURE 2.0 (§ 107) changed the RMD beginning age in two steps:¹

• Born 1951–1959: RMDs begin at age 73.
• Born 1960 or later: RMDs begin at age 75 (the age-75 rule takes effect on January 1, 2033, when the first people born in 1960 would otherwise have reached age 73).

If you were born before 1951 and were already taking RMDs under the old age-72 rule, the change doesn't affect your existing schedule — you continue taking RMDs as normal.

How TSP calculates your RMD

Your RMD for any given year is:

RMD = December 31 prior-year traditional TSP balance ÷ IRS Uniform Lifetime Table factor for your age

The IRS Uniform Lifetime Table (updated in 2022 via T.D. 9930³) assigns a life expectancy factor to each age. The factor reflects the number of years the IRS expects you to receive distributions — it gets smaller each year, so the required percentage drawn out increases as you age.

A few mechanics specific to TSP:

• Roth TSP excluded: TSP tracks traditional and Roth balances separately. Your RMD amount is computed only on the traditional balance. Withdrawals from your Roth balance do not count toward satisfying the RMD.²
• TSP auto-satisfies: Any withdrawals you take from your traditional TSP balance during the year (installments, partial distributions) count toward your annual RMD. If you haven't met the RMD by late March, TSP will automatically issue a supplemental payment before April 1.⁴
• Age used: The factor for the age you turn during the distribution calendar year (not your age at the start of the year).

The first-year RMD doubling trap

For your first RMD only, the IRS gives you until April 1 of the following year (your Required Beginning Date) instead of December 31. This sounds like a grace period — but it's a trap for many federal retirees.

If you delay your first RMD to April 1 of year two, you must also take year two's RMD by December 31 of that same year. Two RMDs in one calendar year means:

• Double the taxable income recognized in a single year
• Potentially a higher marginal tax bracket for that year
• Possible jump into a higher IRMAA tier, raising your Medicare Part B and Part D premiums for two years afterward

In most cases, taking your first RMD by December 31 in the year you reach RMD age is cleaner. The exception: if you retire at the end of the year you reach RMD age and your income will be materially lower next year, deferring to April 1 might make sense — but model it first with your advisor.

TSP RMDs and IRMAA

Traditional TSP withdrawals — including RMDs — count as ordinary income and are included in your Modified Adjusted Gross Income (MAGI) for Medicare's Income-Related Monthly Adjustment Amount (IRMAA).⁵ IRMAA is calculated on your income from two years prior (so 2024 income determines 2026 surcharges).

The 2026 IRMAA thresholds are:⁵

For a federal retiree with a FERS annuity of $65,000/yr plus Social Security, a $30,000 TSP RMD can easily push MAGI above $109,000 — triggering an extra $888/yr ($74/mo × 12) in Medicare surcharges. A specialist can model Roth conversion strategies before RMDs begin to reduce this exposure.

Roth TSP: no lifetime RMDs

Before SECURE 2.0, Roth 401(k) and Roth TSP accounts were subject to lifetime RMDs — unlike Roth IRAs. SECURE 2.0 § 325 eliminated this inconsistency, effective January 1, 2024: Roth TSP balances are no longer subject to lifetime required minimum distributions.²

Practically, this means:

• You can hold Roth TSP indefinitely without being forced to draw it down during your lifetime
• Your RMD is calculated only on your traditional balance — a $200K traditional / $400K Roth split generates far less in taxable RMDs than a $600K all-traditional balance
• Building Roth TSP via catch-up contributions or Roth conversions before retirement materially reduces lifetime RMD exposure

Note: if you roll your TSP to a traditional IRA, RMDs from that IRA are calculated the same way and on the same schedule. The Roth TSP no-RMD rule follows the balance — roll Roth TSP to a Roth IRA and there are still no lifetime RMDs.

TSP rollover vs. staying in TSP for RMD purposes

Both TSP and a rollover IRA generate RMDs on the same schedule and using the same IRS Uniform Lifetime Table. The key practical difference:

• TSP auto-satisfies RMDs. If you stay in TSP, the plan calculates and distributes your RMD automatically. You don't need to track it yourself.
• IRA aggregation rules. If you roll TSP to an IRA and already have other IRAs, your RMD can be taken from any IRA in any combination that totals the required amount. TSP doesn't participate in this aggregation — TSP RMDs must be satisfied from the TSP itself.
• Investment options. The TSP G Fund's unique Treasury-rate-with-no-interest-rate-risk feature is not available in any IRA. Rolling to an IRA gains more investment options but loses this specific fund.

The RMD calculation is identical in both cases. The difference is operational: who calculates it, who distributes it, and whether aggregation flexibility matters to you.