Retirement & Tax Planning Answers
What Are the Tax Implications of Required Minimum Distributions From Retirement Accounts?
Quick answer
A required minimum distribution is taxed as ordinary income in the year it's withdrawn, at your regular federal (and, outside Arizona, often state) income tax rate, not at a lower capital gains rate. Because it stacks on top of Social Security, pension income, and any other withdrawals, an RMD can push you into a higher marginal bracket, increase the taxable portion of your Social Security benefit, and trigger an IRMAA surcharge on Medicare premiums two years later. Custodians typically default to withholding only 10% unless you elect otherwise, which is often less than what's actually owed once the RMD is added to your other income. Missing the deadline carries a penalty, reduced under SECURE 2.0 to 25% of the shortfall, or 10% if corrected within two years.
An RMD pulled from a traditional IRA or 401(k) is fully taxable as ordinary income in the year it's taken, because the money was never taxed going in. There's no special RMD tax rate and no capital gains treatment, even if the underlying account holds long-term investments. The distribution is simply added to your adjusted gross income for the year.
That stacking effect is where most of the real cost hides. Social Security benefits become more taxable as combined income rises, so an RMD can convert benefits that would otherwise be tax-free into taxable income. The same RMD can also push modified adjusted gross income across an IRMAA threshold, adding a Medicare Part B and Part D surcharge that applies for a full year, based on income from two years earlier. A retiree who looks at an RMD in isolation is missing both of these secondary effects.
Withholding is elective, not automatic, at the level most retirees actually need. Most custodians default to withholding 10% for federal taxes unless you request a different percentage or a flat dollar amount, and that default is frequently well below the marginal rate the RMD ends up taxed at once it's stacked with everything else. The gap shows up as an underpayment penalty or a larger-than-expected bill at filing.
The penalty for missing an RMD deadline entirely was cut sharply by SECURE 2.0. It used to be 50% of the shortfall. It's now 25%, and drops to 10% if the missed RMD is corrected within two years. That's meaningfully less punitive than it used to be, but it's still an avoidable cost, and the correction window requires actually noticing the miss and fixing it, not just waiting it out.
Roth IRAs are the one major exception. The original owner of a Roth IRA has no RMD requirement during their lifetime, though inherited Roth IRAs are subject to the SECURE Act's 10-year rule for most non-spouse beneficiaries, even though the withdrawals themselves remain tax-free.
Model your RMD's tax impact before the year it starts, not during it. If a Roth conversion in the years before RMDs begin could shrink the pre-tax balance and reduce future RMDs, that planning window closes once RMDs start and the balance is largely locked into its tax treatment.
Check your withholding election, not just the RMD amount. A 10% default withholding rate is a guess, not a calculation, and it's worth running your actual expected tax rate for the year the RMD stacks with your other income.
- Treating the RMD as a fixed, unavoidable tax cost rather than something that can be planned around years in advance through Roth conversions or QCDs.
- Accepting the custodian's default 10% withholding without checking whether it covers the actual tax owed once the RMD stacks with other income.
- Not checking whether the RMD pushes modified adjusted gross income across an IRMAA threshold, since the surcharge applies a full two years later and is easy to miss until the bill arrives.
- Forgetting that multiple 401(k)s must each satisfy their own RMD separately, while IRA RMDs can be aggregated and taken from any combination of IRAs.