Quick Answer
You can combine RMDs within an account type, but not across types. If you have multiple Traditional IRAs (including SEP and SIMPLE IRAs), calculate each RMD, add them up, and take the total from any one IRA or any mix. The same works separately for 403(b) plans. But 401(k) and other employer plans never aggregate -- each plan's RMD must come from that plan, and you can never use an IRA withdrawal to satisfy a 401(k) RMD. Any amount you fail to withdraw is hit with a 25% excise penalty under SECURE 2.0.
Key Takeaways
- IRAs aggregate: total the RMDs from all your Traditional, SEP, and SIMPLE IRAs and take it from any one or more of them.
- 403(b)s aggregate with other 403(b)s -- but only with each other.
- 401(k)s do not aggregate -- not with IRAs, not with other 401(k)s. Each plan, separately.
- Roth IRAs have no lifetime RMD, so they are not in any aggregation group.
- Missing any bucket's RMD triggers a 25% penalty (10% if corrected within two years via Form 5329).
- The formula is unchanged: December 31 prior-year balance divided by your IRS life-expectancy factor.
Why Aggregation Matters
By the time you reach RMD age -- 73 if you were born between 1951 and 1959, or 75 if you were born in 1960 or later under SECURE 2.0 -- many people hold several retirement accounts: a rollover IRA, a Roth IRA, an old 401(k) from a former employer, and a current 401(k). The question is not just how much you must withdraw, but which account the money has to come from.
Get this wrong and the cost is steep. Under SECURE 2.0, the penalty for failing to take a required distribution is a 25% excise tax on the amount you should have withdrawn but did not -- reduced from the old 50%, and reducible further to 10% if you correct the shortfall within two years and file Form 5329. Because you can take more from an IRA without it counting toward a 401(k) RMD, a simple bookkeeping mistake can leave a 401(k) RMD unmet even though you withdrew plenty of money overall.
The mental model: think of your accounts as separate buckets. IRAs share one bucket. Each 403(b) line shares a 403(b) bucket. Each 401(k) is its own bucket. You must empty the required amount from within each bucket -- you cannot borrow capacity from one bucket to cover another.
The IRA Aggregation Rule
IRAs are the most flexible. Per IRS Publication 590-B, if you own more than one Traditional IRA, you:
- Calculate the RMD for each IRA separately (December 31 prior-year balance ÷ your IRS life-expectancy factor).
- Add those amounts together to get your total IRA RMD.
- Withdraw that total from any single IRA, or any combination of your IRAs.
This group includes Traditional IRAs, SEP IRAs, and SIMPLE IRAs -- they all aggregate together. Roth IRAs are excluded because the original owner never has a lifetime RMD on a Roth IRA.
Why allow this? It is administratively simpler. If you hold a large IRA at one custodian and a small IRA at another, you can satisfy your whole IRA RMD from the larger account and leave the smaller one untouched -- useful if one account holds investments you would rather not sell this year.
Inherited IRAs are a separate group. RMDs from an inherited IRA can never be combined with RMDs from IRAs you own yourself. Keep inherited-account math entirely separate -- see Inherited IRA RMD Rules for the 10-year rule and beneficiary options.
The 403(b) Aggregation Rule
403(b) plans -- common for teachers, hospital staff, and nonprofit employees -- have their own aggregation rule that mirrors the IRA rule but in a separate bucket. If you have more than one 403(b), you can calculate each plan's RMD, total them, and take the combined amount from a single 403(b).
The crucial limit: 403(b)s aggregate only with other 403(b)s. You cannot satisfy a 403(b) RMD from an IRA, and you cannot satisfy an IRA RMD from a 403(b). They are different buckets that happen to share the same internal flexibility.
The 401(k) and Employer-Plan Rule: No Aggregation
This is where most mistakes happen. 401(k) plans -- and other employer plans like 457(b) and profit-sharing plans -- do not aggregate at all. Each plan stands alone:
- You must take each 401(k) plan's RMD from that specific plan.
- If you have two 401(k)s, you take two separate RMDs -- one from each. They do not combine with each other.
- You can never use an IRA withdrawal to satisfy a 401(k) RMD, or a 401(k) withdrawal to satisfy an IRA RMD.
If you dislike juggling multiple 401(k) RMDs, one common planning move is to roll old 401(k)s into a single IRA before RMDs begin. Once the money is in an IRA, it joins the flexible IRA aggregation group. (Rolling over after RMDs start has its own timing rules -- the current-year RMD must be taken before the rollover.)
The number-one RMD aggregation error: taking a larger IRA withdrawal and assuming it covers a 401(k) RMD. It does not. The 401(k) RMD remains unmet and exposed to the 25% penalty, while the extra IRA money is simply taxable income with no benefit. Always satisfy each 401(k) from within that 401(k).
Which Accounts Aggregate? The Master Table
Use this table to confirm whether two accounts share a bucket. Accounts in the same group can satisfy each other's RMDs; accounts in different groups cannot.
| Account Type | Aggregates With | Take RMD From |
|---|---|---|
| Traditional IRA | Other Traditional, SEP & SIMPLE IRAs | Any one or more of your IRAs |
| SEP IRA | Other Traditional, SEP & SIMPLE IRAs | Any one or more of your IRAs |
| SIMPLE IRA | Other Traditional, SEP & SIMPLE IRAs | Any one or more of your IRAs |
| 403(b) | Other 403(b)s only | Any one or more of your 403(b)s |
| 401(k) | Nothing -- stands alone | That specific 401(k) plan |
| 457(b) / profit-sharing | Nothing -- stands alone | That specific plan |
| Roth IRA (owner) | N/A -- no lifetime RMD | No RMD required |
| Inherited IRA | Same-decedent inherited IRAs of the same type | Within that inherited group only |
Source: IRS Publication 590-B and the IRS Retirement Plan and IRA RMD FAQs. The simplest rule to remember: IRAs pool, 403(b)s pool, and everything else stands alone.
Inherited and Spousal Nuances
Inherited accounts add a layer of complexity that trips up even careful retirees:
- Never mix inherited with your own. An RMD from an IRA you inherited cannot satisfy an RMD from an IRA you own, and vice versa.
- Same decedent, same type may pool. If you inherited two Traditional IRAs from the same person, you may aggregate those inherited IRAs with each other.
- Different decedents stay separate. An IRA inherited from a parent and one inherited from a spouse are different buckets.
- Spousal options differ. A surviving spouse who treats an inherited IRA as their own folds it into their personal IRA aggregation group; one who keeps it as an inherited IRA does not.
Because the SECURE Act's 10-year rule reshaped how inherited accounts distribute, confirm your specific path before relying on aggregation. Our Inherited IRA RMD Rules guide walks through eligible designated beneficiaries, the 10-year rule, and annual-RMD requirements in detail.
A Worked Multi-Account Example
Robert turns 75 in 2026, so his life-expectancy factor from the IRS Uniform Lifetime Table is 24.6. He holds two Traditional IRAs and one 401(k). Here are his December 31, 2025 balances and the RMD for each.
| Account | Dec 31, 2025 Balance | Factor | RMD |
|---|---|---|---|
| IRA #1 | $300,000 | 24.6 | $12,195 |
| IRA #2 | $200,000 | 24.6 | $8,130 |
| 401(k) | $250,000 | 24.6 | $10,163 |
| Total required for 2026 | $30,488 | ||
How Robert satisfies it:
- IRA bucket: his two IRAs aggregate, so his combined IRA RMD is $12,195 + $8,130 = $20,325. He can take all $20,325 from IRA #1, all from IRA #2, or split it -- the IRS only cares that $20,325 leaves his IRAs.
- 401(k) bucket: the $10,163 RMD must come out of the 401(k) itself. He cannot cover it by taking more from his IRAs.
So Robert takes a minimum of two withdrawals: $20,325 from his IRAs (in whatever mix he likes) and $10,163 from his 401(k). If he had instead pulled the full $30,488 from his IRAs, his 401(k) RMD would be unmet -- exposing $10,163 to a 25% penalty (about $2,541) until corrected.
Run your own numbers with the RMD Calculator, then use the 2026 RMD Rules guide for the full Uniform Lifetime Table and SECURE 2.0 details.
Frequently Asked Questions
It depends on the account type. If you have multiple Traditional IRAs (including SEP and SIMPLE IRAs), you calculate the RMD for each, add them together, and may take the total from any single IRA or any combination. The same flexibility applies separately to 403(b) accounts. But 401(k) and other employer plans cannot be aggregated: each 401(k) plan's RMD must be taken from that specific plan, and you cannot satisfy a 401(k) RMD from an IRA or vice versa.
No. Per IRS Publication 590-B, you calculate the RMD for each Traditional IRA individually using its December 31 prior-year balance divided by your IRS life-expectancy factor, then add the amounts together. You can take the combined total from one IRA, spread it across several, or any mix. SEP and SIMPLE IRAs are included in this IRA aggregation group; Roth IRAs are excluded because they have no lifetime RMD. Use the RMD Calculator to total each account.
No. IRA RMDs and 401(k) RMDs are calculated and satisfied in separate buckets. You cannot take a larger IRA withdrawal to cover a 401(k) RMD, and you cannot use a 401(k) withdrawal to cover an IRA RMD. If you have two 401(k) plans, each plan's RMD must come out of that plan -- 401(k)s do not aggregate with each other either. Mixing these buckets is one of the most common RMD mistakes and can trigger a shortfall penalty.
If you withdraw the full required amount but from a type that does not satisfy that bucket -- for example, taking extra from an IRA to cover a 401(k) RMD -- the IRS treats the 401(k) RMD as unmet. The shortfall is subject to a 25% excise penalty under SECURE 2.0 (down from 50%), reducible to 10% if corrected within two years via Form 5329. The extra IRA withdrawal still counts as taxable income but does not fix the 401(k) shortfall. When in doubt, take each bucket's RMD from within that bucket.
Only within narrow limits. Inherited IRA RMDs can never be combined with RMDs from IRAs you own yourself. If you inherited multiple IRAs from the same person and they are the same type, you may be able to aggregate those inherited IRAs with each other. But inherited IRAs from different decedents must be kept separate, and an inherited IRA cannot satisfy an inherited 401(k) RMD. See our Inherited IRA RMD Rules guide for the full picture.
Calculate Each Account's RMD
List every retirement account, calculate each RMD from its December 31 balance, then group them by bucket -- IRAs together, each 401(k) on its own -- to know exactly how much to take and from where.
Sources
- IRS - Retirement Plan and IRA Required Minimum Distributions FAQs(opens in new tab)
- IRS - Publication 590-B (Distributions from IRAs)(opens in new tab)
- IRS - Publication 575 (Pension and Annuity Income)(opens in new tab)
- IRS - Form 5329 (Additional Taxes on Qualified Plans)(opens in new tab)
- SECURE 2.0 Act of 2022(opens in new tab)
Important Disclaimer
Disclaimer: This content is for educational and informational purposes only and does not constitute financial, tax, or legal advice. RMD aggregation rules are complex and depend on your specific account types and beneficiary status; you should consult a qualified tax professional or financial advisor before relying on aggregation. Figures cited reflect IRS rules and SECURE 2.0 as understood at publication, including the 25% missed-RMD excise tax (reducible to 10%) and the age-73/75 starting ages. While we strive for accuracy, laws and regulations change frequently. Data current as of June 2026.
Content reviewed by the Digital Calculator Team. Learn more about our accuracy standards.