Last Updated: October 11, 2026 Reading Time: 8 min

If you were born in 1953 and have left federal service, you turn 73 this year, and 2026 is the first year the TSP has to pay you a required minimum distribution. The law lets you wait until April 1, 2027 to take it. The TSP will even send it for you by that date if you do nothing, provided it has your correct birth and separation dates. Waiting is allowed, and in both examples below it is the more expensive choice, because the 2026 and 2027 distributions then land in the same tax year, and the money you left in makes the second one larger. Here is the math at two balances, and when deferring can win.

Who This Applies To

Three rules decide whether this decision is yours.

The age rule: 26 U.S.C. § 401(a)(9)(C)(v) sets the applicable age at 73 for anyone who reaches 72 after December 31, 2022 and 73 before January 1, 2033, which is the 1951 through 1959 birth years. Born in 1953, you reach 73 during 2026.

The separation rule: under 5 C.F.R. § 1650.16(a), only a separated participant must take TSP RMDs. A federal employee still on the rolls at 73 owes no TSP RMD. The first distribution year is then the year of separation, and the first RMD is due April 1 of the following year. A traditional IRA is different: it owes its RMD at 73 whether or not you are still working, under 26 U.S.C. § 401(a)(9)(C)(ii), and that includes an IRA holding money rolled over from the TSP.

The Roth rule: your Roth TSP balance is excluded from lifetime RMDs under 26 U.S.C. § 402A(d)(5), beginning with 2024 RMDs. The TSP's own RMD bulletin says the calculation includes only the traditional balance from 2024 onward.

So the reader of this post is a separated TSP participant born in 1953 with a traditional balance. Anyone 73 or older who separates during 2026 has the same April 1, 2027 date.

The Two Deadlines and the One Year They Share

IRS Publication 590-B puts the two deadlines side by side. The first RMD is due by April 1 of the year after you reach 73. Every later RMD is due by December 31 of its own year. For the 1953 cohort that means the 2026 RMD can be paid as late as April 1, 2027, and the 2027 RMD is due by December 31, 2027.

Both payments are 2027 income if you defer. Under 26 U.S.C. § 402(a), a TSP distribution is taxed in the taxable year in which it is distributed, and under § 402(c)(4)(B) the RMD portion cannot be rolled over to move it somewhere else.

The TSP's default is the deferral. Under 5 C.F.R. § 1650.16(c), if a separated participant's own withdrawals fall short, the record keeper distributes the necessary amount on or before the deadline. The TSP's "All about RMDs" bulletin says it will send a first RMD "by April 1 of the following year," and that it withholds 10% for federal income tax on that payment unless you change the withholding on the ThriftLine. If you do nothing, you have chosen the deferral.

Why Deferring Makes the Second RMD Bigger

Your RMD for a year divides the account balance as of December 31 of the preceding year by the IRS Uniform Lifetime Table divisor for your age that year: 26.5 at 73 and 25.5 at 74 (26 C.F.R. § 1.401(a)(9)-9(c), Table 2). On the Uniform Lifetime Table, which the TSP applies to every participant's automatic payment, a 1953-born participant uses 26.5 for 2026 and 25.5 for 2027, never 26.5 twice. A spouse who is the sole beneficiary and more than 10 years younger changes the tax-law minimum, not the TSP's automatic amount.

The regulation that sets the balance, 26 C.F.R. § 1.401(a)(9)-5(b), subtracts only distributions made in the valuation year itself. A payment made in March 2027 is not in the 2026 valuation year, so it does not reduce the December 31, 2026 balance that sets the 2027 RMD. Money you leave in until 2027 is counted twice: once as the deferred 2026 RMD and again as part of the base for the 2027 RMD.

With a flat balance, the split path produces the same RMD in both years, because (B minus B/26.5) divided by 25.5 equals B/26.5. The deferral path makes the 2027 RMD larger than the 2026 one.

Example 1: $300,000 Traditional Balance

Persona for both examples: single filer, born in 1953, separated before 2026. FERS annuity $45,000, treated as fully taxable. Social Security $24,000, of which 85% ($20,400) is taxable because provisional income exceeds $34,000 in every case here. No other income, so baseline AGI is $65,400. Deductions: the $16,100 standard deduction plus the $2,050 additional amount for an unmarried taxpayer 65 or older (Rev. Proc. 2025-32 § 4.14), plus the $6,000 senior deduction under 26 U.S.C. § 151(d)(5), reduced by 6% of modified AGI above $75,000. Tax uses the 2026 brackets in Rev. Proc. 2025-32 § 4.01 for both years, because the IRS had not published 2027 brackets when this was written (checked October 11, 2026). The TSP balance is held flat so the mechanics are visible.

Path 2026 RMD 2027 RMD Two-year RMD total
Split (take the 2026 RMD in 2026) $300,000 ÷ 26.5 = $11,320.75 ($300,000 − $11,320.75) ÷ 25.5 = $11,320.75 $22,641.51
Defer (take the 2026 RMD by April 1, 2027) $0 in 2026 $11,320.75 plus $300,000 ÷ 25.5 = $11,764.71, both in 2027: $23,085.46 $23,085.46 (+$443.95)
Path 2026 federal tax 2027 federal tax Two-year total
Split $6,300.28 (AGI $76,720.75) $6,300.28 $12,600.56
Defer $4,702.00 (AGI $65,400) $9,043.81 (AGI $88,485.46) $13,745.81

Deferral costs $1,145.25 more over the two years. Splitting uses $9,150 of otherwise-empty 12% bracket room in 2026; deferring pushes $14,745 into the 22% bracket in 2027. Neither path crosses the 2026 first Medicare surcharge threshold ($109,000 single).

Example 2: $800,000 Traditional Balance

Path 2026 RMD 2027 RMD Two-year RMD total
Split $800,000 ÷ 26.5 = $30,188.68 ($800,000 − $30,188.68) ÷ 25.5 = $30,188.68 $60,377.36
Defer $0 in 2026 $30,188.68 plus $800,000 ÷ 25.5 = $31,372.55, both in 2027: $61,561.23 $61,561.23 (+$1,183.87)
Path 2026 federal tax 2027 federal tax Two-year total
Split $10,700.28 (AGI $95,588.68) $10,700.28 $21,400.56
Defer $4,702.00 (AGI $65,400) $18,020.94 (AGI $126,961.23) $22,722.94

Deferral costs $1,322.38 more, and the last dollars cross into the 24% bracket by $229.

The bigger cost is two years out. Medicare uses your tax return from two years earlier (20 C.F.R. § 418.1135(a)), falling back to the third prior year if the newer return is unavailable (§ 418.1135(b)), so 2027 income normally sets 2029 Part B and Part D surcharges. Deferring lifts 2027 modified AGI to about $126,961, above the first surcharge threshold, which in 2026 starts above $109,000 single and $218,000 joint and adds $81.20 a month to Part B (CMS, November 14, 2025). Splitting keeps both years near $95,589, under the line. The 2029 thresholds will be somewhat higher than 2026's and are not published, so treat the 2026 figures as the reference, not as the 2029 surcharge.

One more effect hides inside the stacked year. The $6,000 senior deduction phases out at 6% of modified AGI over $75,000 single ($150,000 joint). Inside that band every extra RMD dollar also removes six cents of deduction, so a 22% bracket dollar is taxed at an effective 23.32% and a 24% dollar at 25.44%. The deduction also requires the qualified individual's Social Security number on the return and, for married taxpayers, a joint return.

Both examples are federal tax only, with no state tax, no basis recovery on the annuity, and no growth on the balance. Rerun them with your own numbers before deciding.

When Deferring Is the Right Call

A 2026 separation can produce a high-income year. Include salary, the annual-leave payout and any buyout in 2026 income only to the extent paid in 2026; account separately for payments received in 2027. If 2026 taxable income sits in the 24% bracket and 2027 drops to the 12% or 22% range, taking the 2026 RMD in early 2027 can save more than the stacking costs. Check Medicare too: 2026 income sets 2028 premiums and 2027 income sets 2029 premiums, so deferral moves the RMD from one test year to the other. Deferral can help when the two-year tax and Medicare-premium comparison favors it. Compare marginal rates, filing status, deductions and IRMAA; higher 2026 income is one possible reason, not a necessary condition.

Everyone else in the cohort, which means anyone already retired for a full year or more, should usually take the 2026 RMD in 2026. April 1, 2027 is the latest date the law allows, and in the examples above waiting for it cost money. Deferral can help when the two-year tax and Medicare-premium comparison favors it. Compare marginal rates, filing status, deductions and IRMAA; higher 2026 income is one possible reason, not a necessary condition.

What to Do Before December 31

  1. Confirm the TSP has your correct date of birth and separation date in My Account. The automatic payment depends on them.
  2. Compute your 2026 RMD: your December 31, 2025 traditional balance divided by 26.5 (a spouse more than 10 years younger who is your sole beneficiary changes the IRS table).
  3. If you want it in 2026 income, request a withdrawal that covers it before year end. An RMD cannot be rolled over.
  4. Decide your withholding. The TSP withholds 10% on an automatic RMD payment unless you change it on the ThriftLine at 1-877-968-3778.
  5. If you miss a required amount, the excise tax is 25% of the shortfall under 26 U.S.C. § 4974(a), reduced to 10% if you take the missed amount from the same plan and file a return showing the tax inside the correction window, which closes at the earliest of an IRS deficiency notice, an assessment, or the last day of the second taxable year after the year the tax is imposed (26 U.S.C. § 4974(e)). You may also request a waiver on Form 5329 if the shortfall resulted from reasonable error and you are taking reasonable steps to remedy it; follow the IRS waiver instructions. For a separated TSP participant with correct records, the TSP's automatic payment makes that rare.

Calculate Both Years

Use the free TSP RMD Calculator to enter your traditional balance and birth year. It works one distribution year at a time: enter your December 31, 2025 balance for 2026, then your December 31, 2026 balance for 2027. It shows what the TSP will send automatically and your required beginning date. Try it now →

Then test the stacked year in the IRMAA Cliff Calculator, which shows where an income lands against the 2026 surcharge brackets, and the bracket leg in the TSP Withdrawal Tax Calculator.

Frequently Asked Questions

I was born in 1953 and retired in 2024. When is my first TSP RMD actually due?

2026 is your first distribution year, and the required beginning date is April 1, 2027 (26 U.S.C. § 401(a)(9)(C)(i)). If you take nothing by then, the TSP sends any unpaid amount on or before that date automatically (5 C.F.R. § 1650.16(c)), as long as your birth and separation dates on file are correct.

If I wait until 2027, do I really owe two RMDs that year?

Yes. The 2026 RMD is due by April 1, 2027 and the 2027 RMD by December 31, 2027, and both are taxed as 2027 income because a TSP distribution is taxed in the year it is paid (26 U.S.C. § 402(a)).

Does the deferred payment at least shrink my 2027 RMD?

No. The 2027 RMD divides your December 31, 2026 balance, which still includes the money you have not taken (26 C.F.R. § 1.401(a)(9)-5(b)). On $800,000 that adds about $1,184 to the 2027 RMD.

I'm 73 and still working for the government. Do I have a 2026 TSP RMD?

No. Only separated participants owe TSP RMDs (5 C.F.R. § 1650.16(a)), so your first distribution year is the year you separate. A traditional IRA is different: it owes an RMD at 73 regardless of whether you are working (26 U.S.C. § 401(a)(9)(C)(ii)).

Does my Roth TSP balance count toward the RMD?

No. Designated Roth accounts are excluded from lifetime RMDs for tax years after 2023 (26 U.S.C. § 402A(d)(5)), and the TSP computes RMDs on the traditional balance only from 2024 RMDs onward.

How do two RMDs in 2027 affect my Medicare premiums?

Medicare looks back two years (20 C.F.R. § 418.1135), so 2027 modified AGI normally sets 2029 surcharges. In the $800,000 example, deferring lifts 2027 modified AGI to about $127,000, over the first tier's 2026 reference threshold of $109,000 for a single filer.

When does deferring make sense?

When 2026 is your high-income year, usually because you separated during 2026 with salary, a leave payout, or a buyout, and 2027 will fall in a lower bracket.

What if the TSP's automatic payment is late or wrong?

A shortfall carries a 25% excise tax (26 U.S.C. § 4974(a)), reduced to 10% if you take the missed amount from the same plan and file a return reflecting the tax inside the correction window, which closes at the earliest of an IRS deficiency notice, an assessment, or the last day of the second taxable year after the year the tax is imposed (26 U.S.C. § 4974(e)). You may also request a waiver on Form 5329 if the shortfall resulted from reasonable error and you are taking reasonable steps to remedy it; follow the IRS waiver instructions. Check your birth and separation dates in My Account now.

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