RMD Aggregation Rules: One Calculation, One Withdrawal? Not Always.

Traditional IRA RMDs can be aggregated: you calculate the RMD for each IRA separately, then withdraw the total from any one account or any combination you choose. 401(k)s and other employer plans cannot: each plan must distribute its own RMD from that specific plan, and inherited accounts never mix with your own. Applying the IRA logic to workplace plans is one of the more expensive compliance mistakes a retiree can make.

How Aggregation Works by Account Type

Traditional IRAs (including SEP and SIMPLE IRAs): Each account's RMD is its December 31 prior-year balance divided by the applicable Uniform Lifetime Table factor, but the total can come from anywhere in the pool. Three IRAs with RMDs of $8,000, $5,000, and $3,000 mean a $16,000 obligation you can pull entirely from the one account that makes the most strategic sense.

401(k)s and other employer plans: No aggregation. A $9,000 RMD from an old employer's 401(k) cannot be satisfied from your current plan or your IRA. Each plan stands alone.

403(b)s: These aggregate with each other, but never across to IRAs or 401(k)s.

Inherited IRAs: These do not aggregate with your own IRAs or with each other. An inherited account's required distribution (under the 10-year rule or life-expectancy rules) must come from that inherited account.

The Traps to Watch

Reach age 73 (the current RMD starting age under SECURE 2.0) with several old 401(k)s and you have separate obligations running in parallel. Miss the distribution from any one of them and you face a 25% excise tax on the shortfall, reduced to 10% if corrected promptly.

A related point comes up regularly: a QCD (Qualified Charitable Distribution) from one IRA can count toward a different IRA's RMD, because both sit inside the traditional-IRA aggregation framework. But a QCD cannot satisfy a 401(k) RMD.

A Worked Example: Three Accounts, Two Different Rules

An illustrative scenario: you are 74 with a traditional IRA at Vanguard ($420,000 prior-year balance), a traditional IRA at Fidelity ($180,000), and a 401(k) at a former employer ($310,000). Using the age-74 Uniform Lifetime Table factor (verify current-year figures, as the IRS updates tables periodically), assume RMDs of roughly $16,300, $7,000, and $12,000 respectively.

The $23,300 IRA obligation can come all from Vanguard, all from Fidelity, or any split. That flexibility matters if one account holds securities you do not want to sell. The $12,000 must come from the old 401(k), on that plan's terms, even if it charges high fees or limits distributions to quarterly windows.

How This Connects to the Broader RMD Picture

Aggregation sits in the Soil layer of your plan, the tax architecture, and getting account structure right before RMDs begin is far less disruptive than reorganizing after distributions are running. For RMD calculations, SECURE 2.0 changes, the inherited-IRA 10-year rule, and how QCDs interact with all of this, the parent page at /strategies/rmds-and-qcds covers the complete picture.

Frequently Asked Questions

Why can't I use my IRA distribution to satisfy a 401(k) RMD?

Because the IRS treats employer plans as separate from IRAs for aggregation purposes. Each 401(k) or 403(b) has a standalone obligation, and an IRA withdrawal does not count toward it.

If I roll my old 401(k) into my IRA before December 31, does that affect my RMD for that year?

If you are past your RMD beginning date, you generally must take that plan's RMD for the year before completing the rollover, because the RMD portion cannot be rolled over. Coordinate the timing with the plan administrator first.

Do inherited IRAs ever aggregate with my own traditional IRAs?

No. Inherited IRAs are tracked separately from your own accounts and from each other, and their required distributions must come from the specific inherited account.

Are Roth IRAs subject to these aggregation rules?

Roth IRAs you own have no lifetime RMD, so the question does not arise during your lifetime. Inherited Roth IRAs follow their own rules under SECURE 2.0.

What to Do Next

What decides this for you. What kind of accounts you hold. Traditional IRAs aggregate, so the total can be taken from any one of them. Workplace plans do not, so each 401(k) must satisfy its own requirement separately. Inherited accounts sit outside both pools entirely.

Where it goes wrong. People with several old 401(k)s apply the IRA logic, calculate the total across everything, take it from the largest account and consider it handled. Every other plan is now short, and the penalty applies per account. It is a rule that punishes the sensible instinct to simplify, and it is invisible until the notices arrive. The same error happens in reverse with inherited accounts, where people satisfy an inherited requirement from their own IRA and leave both wrong.

Worth a conversation if you hold more than one workplace plan, you have inherited an account alongside your own, or you are consolidating and want to know what that does to next year's calculation. Consolidation genuinely does simplify this, but which accounts can merge is a separate question from which should. Book a call.

The information provided is for educational purposes only and does not constitute investment, legal, or tax advice. Tax law changes frequently — verify current rules before acting. Consult with qualified professionals for guidance specific to your situation.