Why Vanguard's Default 10% RMD Withholding Is Too Low

Vanguard RMD Tax Withholding: What the Default Settings Get Wrong

Vanguard's default federal withholding rate on RMDs is 10%. For most FatFIRE retirees, that number is dangerously low. A $5M traditional IRA generates a first-year RMD of roughly $188,679 at age 73, which lands a married couple well into the 32% or 35% federal bracket before Social Security, dividends, or any other income enters the picture. Getting the withholding wrong costs real money.

This article covers the mechanics of Vanguard RMD tax withholding, the specific gaps between Vanguard's defaults and IRS safe harbor requirements, and the higher-order strategies (qualified charitable distributions, Roth conversions, multi-account sequencing) that actually move the needle at $5M+ portfolio levels.

RMD Starting Ages Under SECURE Act 2.0

The original SECURE Act moved the RMD starting age from 70½ to 72. SECURE Act 2.0, passed in December 2022, moved it again. The IRS now requires distributions based on birth year, not a single universal age.

According to Congress.gov, SECURE Act 2.0 also reduced the excise tax on missed RMDs from 50% to 25%, and further to 10% if you correct the shortfall within the IRS correction window. The IRS still imposes the penalty automatically, so the reduction is not a reason to get casual about compliance.

Your first RMD can be deferred until April 1 of the year following the year you reach your applicable starting age. Every subsequent RMD must be taken by December 31. Taking two distributions in one calendar year (because you deferred the first) compresses income and can spike your tax bracket and Medicare surcharges simultaneously. Most high-net-worth retirees are better served taking the first RMD in the calendar year it becomes due.

One 2024 change worth noting: SECURE Act 2.0 eliminated RMDs from Roth 401(k) accounts starting in 2024, aligning them with Roth IRA treatment. If you held a significant Roth 401(k) balance from high-income working years and previously rolled it to a Roth IRA to avoid RMDs, that rollover is no longer necessary for accounts going forward. Review your account structure with your tax attorney if this applies.

How to Calculate Your RMD at a $5M+ Portfolio Level

The IRS Uniform Lifetime Table, detailed in IRS Publication 590-B, divides your prior year-end account balance by a distribution period tied to your age. At 73, the distribution period is 26.5.

A $5M traditional IRA balance at year-end produces a year-one RMD of approximately $188,679. At 80, the distribution period drops to 20.2, pushing the same $5M balance to a $247,525 RMD. The math compounds: as the distribution period shortens and the account balance (if invested) continues growing, RMDs can accelerate faster than many retirees anticipate.

These figures assume a static balance for illustration. In practice, a portfolio growing at 6% annually will produce larger RMDs each year. The IRS calculates each year's RMD from the prior December 31 balance, so strong market performance directly increases your mandatory taxable income.

If you hold retirement assets across multiple accounts, you calculate each account's RMD separately. For traditional IRAs, you can aggregate the total and withdraw it from any single IRA. For 401(k)s, each plan requires its own distribution. Vanguard's RMD calculator handles the per-account math, but the aggregation strategy across custodians requires your own tracking or a coordinated approach with your advisor.

For a deeper look at RMD fundamentals and strategies, including how account type affects your options, that resource covers the mechanics in detail.

Vanguard RMD Tax Withholding: The Default 10% Problem

Vanguard's default federal withholding on IRA distributions is 10%. You can elect zero withholding, a specific percentage, or a flat dollar amount. The flexibility is there. The problem is that most people never change the default.

For FatFIRE retirees, 10% is almost certainly insufficient. IRS Publication 505 specifies the safe harbor rules for avoiding underpayment penalties: you must pay at least 90% of the current year's tax liability, or 100% of the prior year's total tax. If your prior-year adjusted gross income exceeded $150,000, that threshold rises to 110% of the prior year's tax liability.

A retiree with a $188,679 RMD, $50,000 in Social Security income, and $80,000 in qualified dividends faces a combined income well above $300,000. At that level, the marginal federal rate on the RMD alone is 32% to 35%. Withholding 10% leaves a substantial gap, and the IRS charges interest on underpayment from the date each quarterly payment was due, not just at filing.

Your options for closing that gap:

• Increase withholding directly on the RMD. Vanguard allows you to elect any percentage. Setting withholding at 32% to 37% on the RMD itself is straightforward and eliminates the need for quarterly estimated tax payments on that income.
• Make quarterly estimated tax payments. If you prefer to keep the full RMD liquid and invest it temporarily, you can pay the tax in four installments (April 15, June 15, September 15, January 15). This works but requires discipline and accurate projections.
• Use a year-end lump-sum withholding strategy. Unlike wage withholding, IRA withholding is treated as paid evenly throughout the year regardless of when it actually occurs. Taking a small supplemental IRA distribution in December with 100% withholding can cure an underpayment for the entire year, a tactic worth discussing with your tax attorney before year-end.

State tax withholding adds another layer. Rules vary significantly: some states require mandatory withholding, others allow opt-out, and several states (including Florida, Texas, and Nevada) have no income tax at all. Vanguard's withholding interface reflects your state of record, but confirm the current rules with your tax counsel, particularly if you recently changed domicile.

How Qualified Charitable Distributions Reduce Vanguard RMD Tax Liability

The qualified charitable distribution (QCD) is the most underused RMD tool for high-net-worth retirees. Under IRC Section 408(d)(8), IRA owners aged 70½ or older can transfer up to $105,000 annually (indexed for inflation starting in 2024) directly from an IRA to a qualified charity. The distribution counts toward your RMD but does not appear in your adjusted gross income.

That exclusion from AGI is the key. A standard charitable deduction reduces your taxable income, but only if you itemize, and only after the distribution has already inflated your AGI. A QCD keeps the income out of AGI entirely, which matters for three reasons at the FatFIRE level:

1. Medicare IRMAA surcharges. For 2024, Medicare's Income-Related Monthly Adjustment Amount adds up to $594 per month per person in additional Part B and Part D premiums for individuals with MAGI above $500,000. The IRMAA calculation uses a two-year lookback, so a single year of unmanaged large RMDs can trigger $14,256 or more in avoidable Medicare surcharges per couple, two years later. Routing charitable giving through QCDs suppresses MAGI directly.
2. Social Security taxation. The IRS taxes up to 85% of Social Security benefits once combined income exceeds certain thresholds. Lower AGI from QCDs can reduce the portion of Social Security subject to tax.
3. State income tax. Many states follow federal AGI as the starting point for state taxable income. A QCD reduces state tax exposure in those states simultaneously.

For a retiree with a $188,679 RMD who intends to give $100,000 to charity anyway, executing that gift as a QCD rather than a taxable distribution followed by a charitable deduction saves approximately $32,000 to $37,000 in federal tax at the 32% to 35% bracket, plus any state tax benefit.

Vanguard supports QCDs, but the mechanics require attention. The check must be made payable directly to the charity, not to you. Vanguard can issue a check directly or wire funds in some cases. Confirm the process with Vanguard before year-end, as processing times matter. For more detail on executing this at Vanguard, see the guidance on qualified charitable distributions.

Is a Roth Conversion Better Than Taking RMDs for a $3M+ Traditional IRA?

For retirees who reached financial independence early, the window between retirement and age 73 is the most valuable tax planning period most people waste. If you retired at 55 with a $3M traditional IRA and no RMDs for 18 years, that account could grow to $8.6M at 6% annual returns by the time mandatory distributions begin. The RMD on $8.6M at age 73 is approximately $324,528 in year one, and it grows from there.

Roth conversion strategies executed during the low-income years before RMDs begin can permanently eliminate that future obligation. The math favors conversion when:

• Your current marginal rate is lower than your projected rate during RMD years
• You have assets outside the IRA to pay the conversion tax (avoiding a larger distribution to cover the bill)
• You have a long time horizon or heirs who will benefit from tax-free inherited Roth assets

The pro-rata rule under IRC Section 408 complicates this for anyone still attempting backdoor Roth contributions. If you hold large pre-tax IRA balances, the pro-rata calculation taxes a portion of every conversion or non-deductible contribution at ordinary rates. Clearing pre-tax IRA balances through conversions before RMD age closes this problem permanently.

A practical conversion strategy for a $5M traditional IRA might involve converting $200,000 to $400,000 annually during low-income years, staying within the 24% bracket ($201,050 to $383,900 for married filing jointly in 2024) rather than allowing forced distributions at 32% or 35% later. Over a decade, that approach can reduce the taxable IRA balance by $2M to $4M, with the converted assets growing tax-free in the Roth account indefinitely.

Roth IRAs carry no RMDs during the owner's lifetime. Roth 401(k)s, as of 2024, also carry no RMDs. For heirs, inherited Roth accounts still require distributions under the 10-year rule for non-spouse beneficiaries, but those distributions remain income-tax-free. See the discussion of inherited Roth 401(k) tax implications for how this plays out across generations.

Multi-Account RMD Sequencing to Minimize Taxes at the $5M+ Level

The order in which you draw down accounts matters as much as the amounts. Research published in the Journal of Financial Planning demonstrates that strategic sequencing of withdrawals across taxable, tax-deferred, and tax-exempt accounts can meaningfully extend portfolio longevity and reduce lifetime tax burden for high-net-worth retirees.

The conventional advice (spend taxable accounts first, then tax-deferred, then Roth) is not optimal for most FatFIRE retirees. A better framework:

The goal is bracket management: keeping total annual income within a target bracket rather than allowing RMDs to push you into higher territory involuntarily. For a couple with $400,000 in annual spending needs, an $188,679 RMD covers roughly half. The remaining $211,321 can come from taxable accounts at preferential capital gains rates rather than additional traditional IRA withdrawals at ordinary income rates.

For optimal withdrawal sequencing across account types, the interaction between RMDs, capital gains rates, and IRMAA thresholds requires annual recalibration, not a set-and-forget approach.

Vanguard's dynamic spending strategies tool can model spending scenarios, though it does not replace a tax-specific withdrawal sequence analysis from your CPA or tax attorney.

How to Change Your Tax Withholding on Vanguard RMD Distributions

Changing your withholding election at Vanguard is straightforward. Log into your account, navigate to the RMD distribution settings, and update the federal and state withholding percentages or dollar amounts. You can make this change at any time, and it applies to future distributions.

A few practical notes:

• Changes made after a distribution has already processed do not apply retroactively. If you took a January distribution at 10% and realize in March that you need 35%, the January distribution is done. Adjust going forward and consider a supplemental year-end withholding distribution to cover the gap.
• Vanguard's automatic RMD service (which calculates and distributes your RMD annually without manual action) uses whatever withholding election you have on file. If you enrolled in automatic distributions and never updated the withholding from the default, you are likely underwithholding.
• You can elect zero federal withholding if you prefer to manage taxes through quarterly estimated payments. This is a legitimate approach, but it requires you to track the IRS safe harbor thresholds precisely. For taxpayers with prior-year AGI above $150,000, the safe harbor requires 110% of prior-year tax, not just 100%.

For those managing 401(k) withdrawal rules alongside IRA distributions, note that 401(k) withholding elections are separate from IRA withholding elections. Each account type requires its own form or online election. Do not assume that updating your IRA withholding changes your 401(k) distribution withholding.

Inherited IRA RMDs and the 10-Year Rule

SECURE Act 2.0 preserved the 10-year rule for most non-spouse beneficiaries introduced by the original SECURE Act. Under IRC Section 401(a)(9), non-spouse heirs who inherit a traditional IRA must fully distribute the account within 10 years of the original owner's death. The IRS clarified in 2024 that annual RMDs are required within those 10 years if the original owner had already begun taking distributions.

For FatFIRE families, this creates a significant estate planning consideration. A $5M traditional IRA inherited by an adult child in their peak earning years produces mandatory distributions on top of their existing income, potentially at 37% federal rates. The tax drag on an inherited traditional IRA versus an inherited Roth IRA is substantial.

Strategies to address this:

• Convert before death. Roth conversions during the owner's lifetime eliminate the inherited RMD problem for heirs. Inherited Roth IRAs still require distribution within 10 years, but those distributions are income-tax-free.
• Use QCDs to reduce the balance. Routing charitable giving through QCDs during the owner's lifetime reduces the account balance that heirs eventually inherit.
• Name a charitable remainder trust as beneficiary. This approach removes the inherited IRA from the estate while providing income to heirs over time, though it requires careful structuring with an estate attorney.

For inherited IRA RMD calculations specific to Vanguard accounts, the calculator handles the 10-year rule mechanics, but the strategic decision about how to structure the drawdown across 10 years (front-load, back-load, or smooth) requires tax projection modeling.

Spouse beneficiaries retain the option to roll the inherited IRA into their own IRA, resetting the RMD clock to their own age. This is almost always the right move for surviving spouses who do not need the funds immediately.

Avoiding Underpayment Penalties: Safe Harbor Rules for High-Income Retirees

The IRS underpayment penalty applies when you have not paid enough tax throughout the year, regardless of whether you pay a large balance at filing. The penalty is calculated on the shortfall from each quarterly due date, not just the annual total.

IRS Publication 505 specifies three safe harbors:

1. Pay at least 90% of the current year's total tax liability
2. Pay at least 100% of the prior year's total tax liability
3. For taxpayers with prior-year AGI above $150,000: pay at least 110% of the prior year's total tax liability

For a retiree whose prior-year tax bill was $120,000, the safe harbor requires $132,000 in withholding or estimated payments for the current year. Vanguard's 10% default on a $188,679 RMD produces $18,868 in withholding. The gap is $113,132. That gap accrues interest at the IRS underpayment rate (currently 8% annualized as of 2024) from each quarterly due date.

The year-end withholding strategy mentioned earlier is particularly useful here. Because IRA withholding is treated as paid ratably throughout the year (unlike estimated tax payments, which are credited to the quarter paid), a large December withholding election can retroactively cure an underpayment for the entire year. This is a legitimate and commonly used technique. Confirm the mechanics with your tax attorney before executing, as the rules differ for estimated payments.

If you prefer the estimated payment route, consider annuity options for retirement income as a way to create predictable income streams that simplify tax projection and withholding management.

When Vanguard's RMD Tools Are Not Enough

Vanguard's RMD calculator, automatic distribution service, and withholding elections are competent administrative tools. For straightforward single-custodian situations, they work well. The limitations emerge at the FatFIRE level.

Vanguard's tools do not model multi-custodian aggregation. If you hold traditional IRAs at Vanguard, Fidelity, and Schwab, each custodian calculates its own account's RMD. The decision about which account to draw from, and in what amount, to optimize tax efficiency requires external analysis. Vanguard will not tell you that drawing from the Fidelity account this year and the Schwab account next year produces a better outcome.

Fidelity and Schwab offer comparable RMD calculation tools with similar default withholding structures. Schwab's RMD calculator integrates with its portfolio analysis tools, which can be useful for multi-account households. Fidelity's guidance on QCDs, as noted in their 2024 publication on tax-smart strategies for charitable retirees, is particularly detailed and worth reviewing even if you custody assets elsewhere.

None of these tools replace a coordinated annual tax projection. At $5M+ in retirement assets, the difference between an optimized and unoptimized withdrawal strategy can easily exceed $50,000 per year in avoidable taxes. That is the kind of number that justifies a dedicated tax advisor, not just a custodian's online calculator.

References

• Internal Revenue Service -- "Publication 590-B: Distributions from Individual Retirement Arrangements (IRAs)" (2024)
• Internal Revenue Service -- "IRC Section 401(a)(9): Required Minimum Distributions"
• Internal Revenue Service -- "Publication 505: Tax Withholding and Estimated Tax" (2024)
• Congress.gov -- "SECURE 2.0 Act of 2022 (Division T of the Consolidated Appropriations Act, 2023)" (2022)
• Internal Revenue Service -- "IRC Section 408(d)(8): Qualified Charitable Distributions"
• Vanguard -- "How America Saves 2024" (2024)
• Journal of Financial Planning -- "Optimal Withdrawal Sequencing for Retirement Portfolios" (2023)
• Fidelity Investments -- "RMD and QCD: Tax-Smart Strategies for Charitable Retirees" (2024)