The aggregation rules, by account type
| Account type | Aggregation rule |
|---|---|
| Your own traditional, SEP, and SIMPLE IRAs | Aggregate. Calculate each IRA's RMD separately, add them up, and withdraw the total from any one (or any combination) of your IRAs. |
| 403(b) plans | Aggregate with each other. 403(b) RMDs can be combined and taken from any of your 403(b) accounts. |
| 401(k) plans | No aggregation. Each plan's RMD must come out of that plan. A 401(k) RMD cannot be satisfied from an IRA or from another employer's plan. |
| Governmental 457(b) | Generally treated plan-by-plan like 401(k)s. Confirm with the plan administrator. |
| Inherited IRAs | Same decedent only. Inherited IRAs aggregate only with other IRAs inherited from the same person. Inherited from two different people: two separate calculations, two separate withdrawals. Inherited IRAs never aggregate with your own IRAs. |
Worked example: the math, bucket by bucket
The following is a hypothetical illustration with round numbers, showing one person with five different buckets and five different answers. It is not your situation and not advice; your factors come from the IRS Uniform Lifetime Table (your own accounts) and the Single Life Table (inherited accounts).
- Your own IRAs: $180,000 + $120,000 = $300,000. Combined RMD: $300,000 ÷ 23.7 = $12,658.23. You may withdraw the full $12,658.23 from either IRA, split between them, or any combination. One withdrawal from IRA #1 satisfies both.
- 403(b)s: $90,000 + $60,000 = $150,000. Combined RMD: $150,000 ÷ 23.7 = $6,329.11, withdrawable from either 403(b). This bucket is separate from the IRA bucket.
- Old 401(k): $200,000. RMD: $200,000 ÷ 23.7 = $8,438.82, and it must come out of this plan. Taking an extra $8,438.82 from an IRA does not satisfy it.
- Inherited IRA from your mother: $70,000. Separate bucket, separate table. Suppose her regime uses your Single Life Table factor with factor-minus-one, and this year's factor is 10.0 (hypothetical): the RMD is $70,000 ÷ 10.0 = $7,000.00, and it must come out of the inherited IRA. It cannot be folded into any bucket above.
Special situations
- Your own Roth IRAs: no RMDs during your lifetime, so nothing to aggregate.
- Designated Roth accounts in a 401(k): no RMDs since SECURE 2.0 (2024), but the rest of the 401(k) still owes its RMD from the plan.
- Still working: the still-working exception can delay your current employer's plan RMD, which changes the aggregation picture that year. Recheck annually.
- First RMD year: the April 1 extension applies within each bucket on its own schedule, another reason to track each bucket separately.
For the full treatment, see the in-depth guide: RMD Aggregation Rules: Which Accounts Combine and Which Don't.
Sources
- IRS Publication 590-B, Distributions from Individual Retirement Arrangements (IRAs)
- IRS RMD FAQs (Retirement plan and IRA required minimum distributions FAQs)
Frequently asked questions
Can I combine RMDs from multiple IRAs?
Yes. Total the separately calculated RMDs and withdraw the sum from any of your own IRAs.
Can I combine a 401(k) RMD with an IRA RMD?
No. Each 401(k) plan's RMD must leave that plan. 403(b)s are the employer-plan exception: they aggregate with each other.
Can inherited IRA RMDs be combined with my own IRA RMDs?
No, never. Inherited IRAs aggregate only with IRAs inherited from the same decedent.
How do I calculate an aggregated RMD?
Calculate each account's RMD separately (prior December 31 balance divided by your factor), then add the RMDs within each aggregation bucket.
What is the classic RMD aggregation mistake?
Taking everything from an IRA while a 401(k) RMD goes unsatisfied. The 401(k) portion is missed entirely, with a 25% penalty on the shortfall.
Do Roth IRAs aggregate with traditional IRAs for RMDs?
Your own Roth IRAs have no lifetime RMDs, so there is nothing to aggregate.
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