How long will my TSP last with monthly withdrawals?

That depends on three things: the balance, the amount you take, and what the rest earns while it sits there. Enter all three and this tool walks the account forward one month at a time, paying each installment first and growing the remainder, then reports how many installments the balance covers and the year it reaches zero. It also prints the level amount that would make the money last exactly as long as your planning horizon, so you can see how far your chosen figure is from sustainable. If that horizon runs into your RMD years and the level amount is below the required distribution, TSP sends the difference automatically and the money runs out sooner; the result says when.

What are the two kinds of TSP installment payments?

TSP offers a fixed dollar amount and an amount based on life expectancy. For the fixed option you pick the figure, which has to be at least $25 per installment, and the plan has to last at least a year: TSPBK25 says "The minimum duration is one year." So $10,000 at $2,000 a month is not a plan TSP will set up. For the life expectancy option TSP computes it from your age and your entire account balance using an IRS table, and recalculates it every January from your December 31 balance. There is no amount field for the life expectancy option. Both can be paid monthly, quarterly or annually.

Which IRS table does TSP use for life expectancy installments?

It depends on when the payments start. TSP uses the IRS Single Life Table at Treas. Reg. 1.401(a)(9)-9(b) for participants who have not yet reached their RMD age when installments begin. Those participants may switch once to the Uniform Lifetime Table at 1.401(a)(9)-9(c) when they reach RMD age, and the switch cannot be reversed. Participants who have already reached RMD age when payments begin use the Uniform Lifetime Table, with no option to switch back. The Single Life Table has smaller divisors, so it pays more and depletes the account faster.

Why does the calculator ask for my birth year instead of my age?

Because the IRS tables are read at the age you reach on your birthday in each calendar year, not your age on the day a payment goes out. The regulation, 26 CFR 1.401(a)(9)-5(c)(1), uses "the employee's age as of the employee's birthday in the relevant distribution calendar year," and your first RMD year is the year you reach your RMD age. Someone who is 74 at an April first installment and turns 75 in November owes an RMD for that year, at the age-75 factor of 24.6. Your birth year also sets your RMD age from TSP's table: 73 if born before 1960, 75 if born in 1960 or later. TSP's booklet says life-expectancy installments are "based on your age" without saying which convention it uses, so this tool applies the IRS one to both.

What happens if my installments are smaller than my RMD?

TSP fixes it without being asked. The booklet says that if your installments, combined with any other distributions, do not meet the required amount from your traditional balance, TSP will issue a supplemental payment from that balance to satisfy the RMD before the deadline. The practical effect is that your withdrawal in that year is the RMD, not the installment you chose, and the extra money leaves the account on the IRS schedule rather than yours. This calculator models the top-up and flags every year it happens.

At what age do TSP required minimum distributions start?

TSP publishes the answer as a birth-year table: RMD age 73 if you were born before 1960, and 75 if you were born in 1960 or later. The required beginning date is April 1 of the year after the later of two events, reaching that age or leaving federal service. That second half matters: if you are still a federal employee at 75, you have no TSP RMD yet. After the first year the deadline moves to December 31, which is why your second distribution year can carry two RMDs.

Do required minimum distributions apply to my Roth TSP balance?

No. Roth money in the TSP is not subject to lifetime required minimum distributions, and Roth dollars inside an installment payment do not count toward meeting one. TSP computes your RMD from the traditional balance only. That is why this calculator asks what share of your balance is traditional. A participant who is half Roth has half the RMD of an otherwise identical participant who is all traditional.

Can I change my TSP installment amount later?

Yes, but the mechanics are fussier than people expect. Changing the dollar amount, the frequency, the source, or the installment type all require stopping your existing installments and requesting new ones. Only a few changes can be made without stopping payments, such as federal tax withholding and a single-destination direct deposit. There is no way to have TSP raise your installment for inflation automatically, which is why the inflation option here is framed as something you do yourself each January.

Is there an early withdrawal penalty on TSP installments?

Installments based on life expectancy are one of the exceptions to the 10 percent early distribution penalty. The catch is that the penalty can be applied retroactively if you stop those installments or take an additional distribution within five years of starting them or before you turn 59 and a half, whichever comes later. Fixed-dollar installments taken before 59 and a half are generally penalized unless another exception applies, such as separating in or after the year you turn 55.

Calculator

TSP Monthly Withdrawal

Pick a monthly installment and this tool tells you the age your balance hits zero, how much TSP would have to add to meet your required minimum distribution, and the level amount that would actually last your planning horizon.

Reviewed by Jonathan D., 20-year federal employee · Formulas verified against TSP.gov · Updated October 2026

Rule snapshot

Reviewed October 3, 2026. Sources: TSP booklet TSPBK25 (Distributions) · TSP booklet TSPBK26 (Tax Rules about TSP Payments) · Treas. Reg. 1.401(a)(9)-9 (IRS life expectancy tables) · Treas. Reg. 1.401(a)(9)-5 (age in the distribution calendar year) · 26 U.S.C. 401(a)(9)(C). Your inputs stay in your browser. Nothing is sent to a server and nothing is saved.

Your account

TSP balance

Share in the traditional balance, percentRequired minimum distributions count only traditional money. Roth TSP has no lifetime RMD.

Your birth yearSets your RMD age from TSP's table (73 if born before 1960, 75 if 1960 or later) and the age the IRS tables use each year: the age you reach on your birthday that calendar year.

First installment

You turn 62 in 2027. A later start month makes the first year a partial year.

Your installments

Installment typeThese are the only two TSP offers. Life expectancy has no amount field.

Frequency

Amount per monthTSP floor is $25 per installment.

Expected annual return, percent

Planning horizon for the safe amount, yearsHow long the money has to last.

Raise my installment every January to keep pace with inflation, at percent a year. TSP does not do this for you.

At $2,500 per month, the balance runs out in the year you turn 96, after 411 monthly installments (34 years 3 months of payments) totalling $1,026,082.

Your money runs out at

Age 96 (2061), after 34 years 3 months of installments

At $2,500 per month, the balance runs out in the year you turn 96, after 411 monthly installments (34 years 3 months of payments) totalling $1,026,082.

Your installment plan
First installment (per month)	$2,500
Paid out in 2027	$30,000
Installments paid	411 (34 years 3 months)
Age the balance hits zero	96, in 2061
Total paid out	$1,026,082
Your RMD age	75
First RMD	$16,144 for 2040, the year you turn 75
Automatic RMD top-ups	None needed
Safe level amount over 30 years	$2,640 per month

RMD floor check. Your installments stay at or above every required minimum distribution in this projection, so TSP never has to add a supplemental payment. The TSP RMD Calculator shows the yearly figure on its own.

How we got this

Starting balance $500,000, 100 percent traditional, paid monthly (12 installments a year).
Ages are the age you reach on your birthday in each calendar year, which is how the IRS tables are read (26 CFR 1.401(a)(9)-5(c)(1): "the employee's age as of the employee's birthday in the relevant distribution calendar year"). Your first installment falls in the year you turn 62.
Each installment of $2,500 comes out first, then the remaining balance grows.
Growth: 5 percent a year as an effective annual rate, applied monthly at (1 + 0.05)^(1/12) - 1, so a full year with no withdrawals grows by exactly 5 percent. A rate quoted as nominal and divided by 12 would compound to slightly more.
Your RMD applicable age is 75 (born 1960 or later), per the table TSP publishes in TSPBK26.
First RMD in the year you turn 75: the traditional balance divided by the Uniform Lifetime factor 24.6 = $16,144.
Your installments stay at or above every RMD, so no supplemental payment is needed.
Level installment that would exactly exhaust $500,000 over 30 years at 5 percent (effective annual, first payment at the start): $2,640 per installment.

RMDs count only your traditional balance. Roth money in the TSP is not subject to lifetime RMDs, and Roth dollars inside an installment do not count toward meeting one.

If you are still a federal employee, no TSP RMD applies yet. The required beginning date is April 1 of the year after the later of reaching your applicable age or leaving federal service.

Installments stop when the balance reaches zero. They are not an annuity and carry no guarantee of lifetime income.

What this models, and what it does not

Scope of the TSP monthly withdrawal calculator: what the engine accounts for and the limits you should know before setting up installments
Modeled	Not modeled
Both installment types TSP actually offers: a fixed dollar amount with the $25 floor and the one-year minimum duration, and life-expectancy payments recalculated each January.	Partial distributions, a total distribution, and the TSP life annuity. Those are separate withdrawal options with different rules.
Ages as the IRS reads them: the age you reach on your birthday in each calendar year (26 CFR 1.401(a)(9)-5(c)(1)), from your birth year. The first year runs from your start month to December.	Your exact birthday and payment day. TSPBK25 says life-expectancy installments are "based on your age" without naming a convention; if TSP uses the age on the payment date, a plan that starts before your birthday gets the next-younger factor in its first year. How TSP sizes a life-expectancy installment in a first year that starts after January is also unpublished; the tool pays each first-year installment at the full-year rate and says so on the result.
TSP's one-year minimum duration for fixed installments, applied at a zero return: one full year of installments has to fit inside your balance, or the tool refuses the plan.	TSP's own duration test, which uses "an assumed earnings rate" it does not publish. A plan within a few percent of the one-year line could be treated differently by TSP.
The IRS Single Life Table and Uniform Lifetime Table from Treas. Reg. 1.401(a)(9)-9, including the one-way switch at RMD age. The Single Life Table is carried from age 45 up, and life-expectancy installments are refused below 45 rather than estimated.	Single Life factors below age 45, which this tool does not carry. The published table runs lower (age 30 is 55.3), so a projection for a younger separated participant has to come from the regulation itself. Also not modeled: the Joint and Last Survivor Table, which applies when a sole beneficiary spouse is more than 10 years younger.
The RMD computed on your traditional balance only, with just the traditional share of each installment counted toward satisfying it, and the automatic supplemental payment taken from the traditional side.	Your choice of withdrawal source. TSP lets installments come from traditional first, Roth first, or pro rata; this tool assumes pro rata, and the other two change how much of each payment counts toward the RMD.
RMD age 73 or 75 by birth-year group, with the RMD computed on the traditional balance using the Uniform Lifetime Table.	The 1959 birth cohort edge case. The statute assigns it both 73 and 75, the regulation is still reserved, and TSP treats it as 73.
The supplemental payment TSP adds automatically when installments fall below the RMD, flagged by year.	Beneficiary participant accounts, where the RMD is computed on the total balance including Roth.
A single flat return read as an effective annual rate: with no withdrawals the balance grows by exactly that percentage in a year. It is applied monthly at (1 + r)^(1/12) - 1, each installment paid before that month's growth.	Market sequence risk, fund expense ratios, inflation, and any year you change the amount. Figures are nominal dollars.
Gross dollars leaving the account.	Federal and state tax withholding, the 10 percent early distribution penalty, and the different withholding rules for installments expected to last under 10 years.
The level amount that exactly exhausts your balance over the horizon you set, checked against the same projection: when that amount falls below your RMD and TSP's automatic top-ups would empty the account before the horizon, or leave the last installment short by $25 or more, the result relabels it as an ignoring-RMDs figure, names the first year it falls below the RMD, and gives the age the money actually runs out and how short the installments fall.	Any guarantee. Installments stop when the balance reaches zero. This is not lifetime income.

Precision limits: the projection steps one month at a time, pays any installment due that month first and then applies a month of growth, so it will differ slightly from a daily-valuation model. The return is an effective annual rate; a 5 percent rate quoted as nominal and divided by 12 would compound to about 5.12 percent. TSP has not published how it divides a life-expectancy annual figure across monthly or quarterly payments, so per-installment amounts in that mode are the annual figure divided evenly. Treat the dollar figures as planning estimates, not as a quote from TSP.

Installments are not an annuity

This is the part that catches people. TSP installment payments keep coming until you stop them or the balance reaches zero, whichever happens first. Nobody is guaranteeing the income for life. Pick a number that is too high and the projection above will show you the age the account empties, which is the single most useful figure on this page.

If you want income that cannot run out, that is the TSP life annuity, a different option with different tradeoffs. Installments buy you flexibility and keep the balance yours. They also put the longevity risk on you.

Fixed dollars or life expectancy

Fixed-dollar installments do what they say: you name the figure, with $25 as the floor, and it stays there until you change it. The amount does not rise with inflation on its own, and changing it means stopping your installments and starting new ones. At 2 percent a year inflation, which is an assumption and not a forecast, twenty years leaves a flat figure buying about two thirds of what it did at the start (1 divided by 1.02 to the 20th power is 0.67). Higher inflation cuts deeper.

Life-expectancy installments hand the arithmetic to TSP. Every January it divides your prior December 31 balance by a factor from an IRS table and pays that out over the year. The payment moves with your balance, which means it falls in a bad market year and rises in a good one. Because each payment is a fraction of what is left, it does not run out early, although far out in the table the factor drops to 2 or below and each year then pays out half or more of the remainder. Which table applies turns on timing: start before your RMD age and you are on the Single Life Table, which pays considerably more. Start at or after RMD age and you are on the Uniform Lifetime Table. The one-time switch from Single Life to Uniform Lifetime at RMD age cannot be undone, so run it both ways in the tool before you commit.

The RMD floor you cannot withdraw below

Once you are separated and past your RMD age, your installments stop being the only thing that decides how much leaves the account. TSP computes your required minimum distribution from your traditional balance and the Uniform Lifetime Table, and if your installments come in short it sends a supplemental payment from the traditional balance to cover the gap. You do not have to request it.

That is convenient and it is also a tax event you did not plan. The calculator highlights every year a top-up fires and totals the dollars involved, so you can see the point where a modest installment stops being a choice. For the RMD figure on its own, use the TSP RMD Calculator. Roth money is not in the RMD base at all, which is one practical reason to hold some of the balance on the Roth side.