Required Minimum Distributions (RMDs): How to Calculate Yours and Avoid Penalties

If you own a traditional IRA, SEP IRA, SIMPLE IRA, or a workplace plan like a 401(k) or 403(b), the IRS eventually wants you to start withdrawing money — and paying tax on it. That withdrawal is your Required Minimum Distribution, or RMD. The math takes about ten minutes once you have the right numbers in front of you. The deadline is firm: December 31 most years, with a one-time grace period to April 1 the year after you turn 73. Miss it, and the IRS can charge an excise tax of up to 25% of the amount you should have withdrawn, according to IRS.gov.

This guide walks through exactly how to calculate your RMD, what documents to pull first, and the mistakes that trigger penalty notices.

Before You Start: What to Gather

Your date of birth. RMD age depends on your birth year.
December 31 balance for each retirement account, from last year’s year-end statement (this year’s RMD is based on last year’s balance, not today’s balance).
A list of every account subject to RMDs — traditional IRAs, SEP IRAs, SIMPLE IRAs, 401(k)s, 403(b)s, 457(b)s, and inherited retirement accounts.
Your spouse’s birth date, if your spouse is your sole primary beneficiary — this can change which IRS table you use.
Access to the IRS Uniform Lifetime Table, found in IRS Publication 590-B at IRS.gov. Most people use this one.

Note what’s exempt: Roth IRAs never require RMDs during the original owner’s lifetime. Starting in 2024, Roth accounts inside employer plans (Roth 401(k), Roth 403(b)) were also freed from lifetime RMDs, under changes made by SECURE 2.0. If all your retirement savings sit in Roth accounts, you can skip this whole process.

Step 1: Confirm You’re Actually Subject to an RMD This Year

Under SECURE 2.0, the RMD starting age is 73 for people born in 1951 through 1959. It rises to 75 for anyone who reaches age 73 after December 31, 2032 — generally people born in 1960 or later — which means the first age-75 RMDs come due in 2035. So for 2026, if you turn 73 at any point in 2026 or earlier, you’re in the RMD system. 2026 is your first RMD year if you turn 73 this year — that first distribution can be delayed until April 1, 2027, but it is still a 2026 RMD.

Two exceptions worth knowing:

Still-working exception. If you’re still employed and own less than 5% of the company sponsoring your 401(k) or 403(b), you may be able to delay RMDs from that specific plan until you retire. This doesn’t apply to IRAs.
Inherited accounts. If you inherited an IRA or 401(k), different rules apply — often the 10-year rule under SECURE Act 1.0, sometimes with annual RMDs required within that window depending on who you inherited from and when. That’s a separate calculation from this article; see IRS Publication 590-B for inherited-account tables.

Step 2: Pull the December 31 Balance for Each Account

Your RMD for 2026 is based on the fair market value of each account as of December 31, 2025 — not the balance today, and not an average. This number appears on the year-end statement your custodian mails or posts online in January. If you can’t find it, call the custodian directly; they’re required to report it to you and to the IRS on Form 5498.

Step 3: Pick the Right IRS Life Expectancy Table

Most retirees use the Uniform Lifetime Table in Publication 590-B. There’s one exception: if your spouse is your sole primary beneficiary for an account and is more than 10 years younger than you, you use the Joint and Last Survivor Table instead, which produces a smaller RMD because it factors in the younger spouse’s longer expected lifespan. Everyone else — single, married to someone closer in age, or with a non-spouse or multiple beneficiaries — uses the Uniform Lifetime Table.

Step 4: Look Up Your Distribution Period (the “Factor”)

Find your age as of your birthday in the RMD year (2026, in this example) on the Uniform Lifetime Table. Selected factors, current under the table the IRS updated effective 2022:

Age	Distribution Period
73	26.5
75	24.6
78	22.0
80	20.2
85	16.0
90	12.2

Confirm your exact factor on IRS.gov, since the full table runs from age 72 through 120+.

Step 5: Divide Each Account Balance by the Factor

The formula:

RMD = Prior year-end account balance ÷ IRS distribution period

Worked example: Maria turns 76 in 2026. Her traditional IRA held $412,000 on December 31, 2025. At age 76, her Uniform Lifetime Table factor is 23.7.

$412,000 ÷ 23.7 = $17,383.97, rounded to $17,384.

That’s the minimum she must withdraw from that IRA in 2026. She can take more if she wants, but not less — and taking extra from one account doesn’t reduce what’s required from a different, unrelated account (with one exception, covered next).

Step 6: Calculate Each Account Separately, Then Decide How to Withdraw

Do this calculation for every account you own. Then the rules differ by account type:

IRAs (traditional, SEP, SIMPLE): You calculate the RMD for each IRA separately, but you can add up the total and withdraw it from any one IRA or combination of IRAs you choose. You don’t have to take a slice from each account.
403(b) accounts: Same aggregation rule applies — combine and withdraw from any 403(b) you own.
401(k), 457(b), and other employer plans: No aggregation allowed. You must calculate and withdraw the RMD separately from each employer plan account.

If you have an old 401(k) and a traditional IRA, you cannot use the 401(k) withdrawal to cover the IRA’s RMD, or vice versa. Keep them in separate buckets.

Step 7: Take the Distribution by the Deadline

For every year after your first RMD year, the deadline is December 31. For your very first RMD — the year you turn 73 — you get an extension to April 1 of the following year. This sounds like a bonus, but it has a catch: if you wait until that April 1 deadline, you’ll owe two RMDs in that same calendar year — the delayed one and the current year’s regular one, due by the following December 31. Two distributions landing in one tax year can push you into a higher tax bracket and increase Medicare IRMAA surcharges. Many retirees are better off just taking the first RMD in the year they turn 73, even though the calendar technically allows a delay.

To actually take the RMD, contact your IRA custodian or plan administrator and request a distribution. You can have it sent as cash, moved to a taxable account, or, in the case of an IRA, sent directly to a qualified charity as a Qualified Charitable Distribution (QCD), which satisfies the RMD without adding to your taxable income. The QCD limit is indexed for inflation each year — it was $108,000 for 2025 and is $111,000 per individual for 2026 (IRS Notice 2025-67).

Step 8: Recalculate Every Year

RMDs aren’t a set-it-and-forget-it number. Each year, you repeat Steps 2 through 5 using the new December 31 balance and your new age. Market gains or losses, additional contributions (in the case of SEP/SIMPLE), and moving up a year on the distribution table all change the dollar amount annually.

Mistakes That Trigger Penalties or Delays

Using the wrong year’s balance. The RMD is based on the prior December 31, not the current balance. Using today’s number produces the wrong figure.
Forgetting an old 401(k). People roll over their most recent employer plan but forget a 401(k) from a job they left 15 years ago. That account still owes its own separate RMD.
Assuming Roth 401(k) rules match Roth IRA rules. Before 2024, Roth 401(k)s did require RMDs even though Roth IRAs never did. That changed with SECURE 2.0, but people relying on old advice sometimes still take an unnecessary distribution — not a penalty, just an avoidable tax event if not planned for.
Waiting until December 31 to request the distribution. Custodians need processing time. A request submitted December 29 may not settle before the deadline. Aim to initiate withdrawals by early December.
Missing the RMD entirely. SECURE 2.0 lowered the excise tax on a missed RMD from 50% to 25% of the shortfall, and to 10% if you correct the mistake within the IRS’s correction window (generally by the end of the second year after the year the RMD was due), according to IRS guidance. You fix a missed RMD by taking the missed amount immediately and filing Form 5329 with your tax return to report the penalty or request a waiver for reasonable cause.

Checking Your Work and What Happens Next

Your custodian typically calculates and reports an estimated RMD amount on your year-end or January account statement for IRAs — but you’re legally responsible for the number being correct, especially across multiple accounts and 401(k) plans they don’t see. Cross-check their figure against your own math using Publication 590-B.

If you took the correct RMD, no additional IRS form is needed beyond reporting the distribution as income on your tax return (it appears on Form 1099-R, which the custodian sends by January 31). If you missed or under-withdrew, file Form 5329 to report and, if eligible, request the penalty be reduced or waived for reasonable cause. For account-specific questions, your plan administrator or IRA custodian can confirm balances and process the withdrawal; for rule questions, IRS Publication 590-B and the IRS RMD FAQ page at IRS.gov are the authoritative references.

Sources

IRS, “Retirement Topics — Required Minimum Distributions (RMDs),” IRS.gov
IRS, Publication 590-B, “Distributions from Individual Retirement Arrangements (IRAs),” IRS.gov
IRS, “Retirement Plan and IRA Required Minimum Distributions FAQs,” IRS.gov
IRS, “SECURE 2.0 Act Changes Affecting Retirement Plans,” IRS.gov

This article is for general information only and is not financial, legal, or tax advice. Program rules change and vary by state — always confirm details with the official agency (.gov) before acting.