Why Withdrawal Order Matters More Than Most People Think
Two retirees walk into retirement with identical portfolios, identical spending plans, and identical investment returns. Twenty years later, one has $400,000 more in net worth, has paid far less in lifetime taxes, and is leaving a larger estate to heirs. Same starting point. Same market. Same life. The only difference: the order in which they drew from their accounts.
This isn't a marginal optimization. Academic research and practitioner case studies consistently show that thoughtful withdrawal sequencing can add 2–5+ years of portfolio longevity, reduce lifetime taxes by $100,000–$300,000 on mid-sized portfolios, and leave materially more to heirs — all without earning an extra dollar of return.
The reason is taxes, and specifically which taxes. Every dollar pulled from a traditional IRA or 401(k) is taxed as ordinary income. Every dollar pulled from a Roth is tax-free. Every dollar from a taxable brokerage account might be taxed at long-term capital gains rates — or at 0% if the retiree's income is low enough — or not at all if it's a return of cost basis. Sequencing determines which of these buckets is being drawn on in each year, which tax bracket the retiree sits in at the time, and what second-order costs (IRMAA, Social Security taxation, ACA subsidy loss) the withdrawals trigger.
It's Not About This Year's Tax Bill
Withdrawal sequencing isn't about minimizing taxes today — it's about minimizing the total lifetime tax burden across a 25–30 year retirement. Sometimes the right move is paying more taxes now (through strategic Roth conversions or deliberate traditional IRA draws at low rates) because it prevents far larger tax bills later. The measuring stick is lifetime, not annual.
The Conventional Wisdom: Taxable → Tax-Deferred → Tax-Free
Most advisors learn a simple default order in their first year of practice:
- Draw from taxable brokerage accounts first. Capital gains rates are lower than ordinary income rates, and you're spending down the least tax-advantaged bucket.
- Then draw from tax-deferred accounts (Traditional IRA, 401(k), 403(b), TSP) once taxable accounts are depleted.
- Leave Roth accounts for last, letting them grow tax-free as long as possible.
The logic is intuitive: preserve tax-advantaged compounding for the longest time horizon, and spend down the least protected money first. It's simple to explain to clients and easy to implement. For decades, it was the default recommendation in every retirement planning textbook.
And for a meaningful share of retirees, it's the wrong answer.
Where the Conventional Wisdom Breaks Down
The default sequence was designed for a world where tax brackets stayed flat, RMDs didn't exist, Medicare premiums were flat-rate, and Social Security wasn't taxed. None of those are true anymore. Here are the four places where blindly following the conventional order gets expensive.
The RMD Tax Bomb
If a retiree preserves their traditional IRA by drawing from taxable accounts first, the pre-tax balance keeps compounding untouched. Required Minimum Distributions kick in at age 73 under current rules (rising to 75 for those born in 1960 or later under SECURE 2.0), and by then the balance may be far larger than the retiree anticipated.
Consider a retiree who stops working at 65 with $1.2 million in a traditional IRA. Assuming 6% growth and no withdrawals, that balance grows to roughly $1.9 million by age 73. The first-year RMD is approximately $72,000 — and every dollar is ordinary income, stacked on top of Social Security and any other income. A retiree who could have been drawing $60,000–$80,000/year in the 12% bracket during the gap years suddenly finds themselves with $110,000+ of forced income in their mid-70s, pushing them into the 22% or 24% bracket for the rest of their lives.
Those "gap years" between retirement and RMD age are often the lowest-income, lowest-bracket period a person will ever have. Failing to use them is one of the most expensive mistakes in retirement planning.
The Gap Years Are Golden
The period between retirement and age 72–73 — before RMDs force the issue, and often before Social Security is claimed — is typically the lowest-bracket window a retiree will ever see. A couple in this window may have $30,000–$90,000 of unused room in the 10% and 12% brackets every single year. Skipping those windows doesn't save taxes — it defers them to a year when brackets and RMDs make them much more expensive.
IRMAA Bracket Creep
Medicare Part B and Part D premiums are income-tested through the Income-Related Monthly Adjustment Amount (IRMAA), using Modified Adjusted Gross Income from two years prior. Cross an IRMAA threshold by a single dollar and the surcharge applies to the entire year — it's a cliff, not a gradient. Poorly sequenced withdrawals can push retirees into a higher IRMAA tier and cost them $1,000–$6,000+ per person per year in added Medicare premiums. The conventional order ignores IRMAA entirely.
| 2025 MAGI (Individual) | 2025 MAGI (MFJ) | Total Monthly Part B | Additional Annual Cost* |
|---|---|---|---|
| $106,000 or less | $212,000 or less | $185.00 | $0 (standard) |
| $106,001 – $133,000 | $212,001 – $266,000 | $259.00 | ~$1,780 per person |
| $133,001 – $167,000 | $266,001 – $334,000 | $370.00 | ~$3,110 per person |
| $167,001 – $200,000 | $334,001 – $400,000 | $480.90 | ~$4,440 per person |
Additional annual cost vs. the standard premium, including Part B surcharge plus a typical Part D surcharge. Thresholds and premiums are adjusted annually by CMS and use a two-year MAGI lookback, so 2025 premiums are based on 2023 tax returns.
Social Security Taxation Triggers
Up to 85% of Social Security benefits become federally taxable once "provisional income" exceeds certain thresholds — roughly $44,000 for married filing jointly and $34,000 for single filers. Provisional income includes AGI plus tax-exempt interest plus 50% of Social Security benefits. Traditional IRA and 401(k) withdrawals count. Roth withdrawals do not. Return of basis from taxable accounts does not.
This means a retiree blindly pulling from a traditional IRA can inadvertently cause their own Social Security to become taxable. The effect is a phantom marginal rate — every additional dollar of IRA withdrawal not only triggers its own tax, it also drags more Social Security into the taxable column, so the effective marginal rate can hit 22.2% or 40.7% even when the stated bracket is only 12% or 22%. Retirees don't see these spikes on their tax bracket chart; they just see a tax bill that seems disproportionate to their income.
Loss of ACA Subsidies (Pre-65 Retirees)
For retirees who leave work before Medicare eligibility at 65, ACA marketplace plans are usually the only practical health coverage. Premium tax credits are income-tested on MAGI and can easily exceed $10,000–$20,000 per year for a couple. Traditional IRA withdrawals count as MAGI. Roth withdrawals and return-of-basis from taxable accounts do not.
A retiree between 55 and 65 who draws $40,000 from a traditional IRA for living expenses might lose $15,000 in subsidies — an effective 37.5% marginal cost on that withdrawal, on top of the federal and state income tax. Sequencing matters enormously in these pre-Medicare years, and the conventional order is often the worst possible choice for households on the marketplace.
A Smarter Approach: Dynamic Tax-Aware Sequencing
Modern withdrawal strategy isn't a fixed order. It's a year-by-year decision that optimizes across tax brackets, IRMAA thresholds, Social Security taxation, ACA subsidies, and long-term account balances. The core technique is bracket filling.
Bracket Filling
Bracket filling is deceptively simple to describe: each year, determine how much room exists inside the current (lower) tax bracket after accounting for all other income — Social Security, pensions, interest, dividends, part-time work. Then deliberately withdraw or convert from the traditional IRA up to the top of that bracket. The goal isn't to cover spending — it's to harvest the cheap bracket space before it's wasted.
A concrete example. A married couple, both 66, both retired. Social Security is deferred until 70. A small pension pays $24,000/year. No other income.
- Gross income: $24,000 pension
- Standard deduction (2025, both over 65): ~$32,300
- Taxable income before any IRA withdrawal: $0 (the deduction fully covers the pension)
- Room in the 10% bracket (2025 MFJ top: $23,850): $23,850
- Room in the 12% bracket (2025 MFJ top: $96,950): an additional $73,100
This couple could withdraw approximately $97,000 from their traditional IRA in a single year and pay an effective federal tax rate of roughly 10.5%. If they do nothing for seven years and wait for RMDs at 73, they will likely pay 22% or more on much of the same money — plus whatever TCJA sunset rates are in force by then. Running this playbook every year during the gap years routinely saves $100,000–$200,000 in lifetime taxes on mid-sized portfolios.
The money withdrawn doesn't have to be spent. It can be reinvested in a taxable account, gifted, or — most powerfully — converted into a Roth IRA.
Roth Conversions Are Withdrawal Sequencing's Best Friend
Bracket filling and Roth conversions are the same mechanic viewed from two angles. You take traditional IRA dollars, recognize them as income while you're sitting in an artificially low bracket, and pay the tax. With a withdrawal, you spend the proceeds. With a conversion, you move them into a Roth to grow tax-free forever. Either way, you've eliminated future RMD exposure on those dollars and locked in a known low rate instead of betting on an unknown future one.
The Role of Taxable Accounts in Sequencing
Taxable brokerage accounts are too often treated as "the first bucket to empty." They deserve better. Taxable accounts offer three unique features that no other account type can match:
- 0% long-term capital gains rates for filers whose taxable income sits inside the 10% or 12% federal ordinary-income bracket. A retiree filling the 12% bracket with traditional IRA income can still realize capital gains on top of that — potentially at 0% — because the 0% long-term rate applies to the bracket-space layering below the 15% rate threshold.
- Tax-loss harvesting during market drawdowns, which can offset gains or up to $3,000 of ordinary income per year and carry forward indefinitely.
- Step-up in basis at death, which erases unrealized capital gains for heirs and makes appreciated taxable holdings one of the most efficient legacy vehicles available.
Rather than reflexively spending them first, taxable accounts should be drawn strategically — harvesting losses in bad market years, realizing gains at 0% when bracket space is available, spending low-basis lots when brackets allow, and preserving highly appreciated lots for the step-up.
When to Use Roth
Roth accounts aren't just "use last." Strategic Roth deployment includes:
- Ducking under IRMAA cliffs. A retiree who's about to cross an IRMAA threshold from a large one-time expense (new roof, medical bill, helping a child with a down payment) can fund the expense from the Roth to keep MAGI below the surcharge line.
- Funding spending during conversion years. If you're converting $80,000 from traditional to Roth, the conversion itself is taxable income — but your living expenses don't have to also come from the traditional IRA. Use Roth or taxable for the spending so the conversion gets the full bracket budget.
- Shock absorbing unexpected expenses. In a year when a surprise cost would otherwise force a retiree into a higher bracket or past an IRMAA line, the Roth absorbs the shock without creating any taxable event.
A Side-by-Side Comparison
To make this concrete, consider two couples with identical starting conditions: age 65, $1,800,000 portfolio (40% traditional IRA, 30% Roth, 30% taxable), Social Security of $48,000/year claimed at 70, annual spending need of $85,000 (growing 3%/year), retiring at 65 and projecting to 85.
| Metric | Retiree A: Conventional | Retiree B: Dynamic |
|---|---|---|
| Sequencing rule | Taxable first, then Trad IRA, Roth last | Bracket fill every year; Roth converted during gap years |
| Roth conversions (years 1–8) | $0 | ~$60,000/yr at 12% bracket |
| First RMD at age 73 | ~$73,000 | ~$34,000 |
| 20-year cumulative federal taxes | ~$287,000 | ~$168,000 |
| Average effective federal tax rate | ~17.4% | ~10.8% |
| IRMAA surcharges paid (cumulative) | ~$42,000 | ~$8,000 |
| Social Security subject to tax | 85% most years | 50–85% variable |
| Roth balance at year 20 | ~$880,000 | ~$1,340,000 |
| Portfolio balance at year 20 | ~$1,510,000 | ~$1,680,000 |
| Tax/IRMAA advantage | — | ~$153,000 |
Illustrative numbers based on a 6% average return, 3% inflation, and current 2025 tax brackets held constant (real-world results will vary with markets, legislation, and individual circumstance). The goal is the magnitude and direction, not precision.
The dynamic approach doesn't just save taxes. It produces a larger Roth balance (better for heirs and for late-retirement flexibility), shrinks RMDs by reducing the traditional balance early, and avoids most of the IRMAA surcharge drag that the conventional sequence walks into.
Common Mistakes in Withdrawal Sequencing
Even advisors who know better fall into these traps:
- Leaving the 0% bracket on the table. A retiree with enough deductions to zero out taxable income has a free bracket of roughly $32,000 every year. Failing to at least convert traditional IRA dollars up through the standard deduction and the 10% bracket wastes it irretrievably.
- Converting too aggressively. Jumping into the 24% or 32% bracket to "get it over with" usually destroys the value. The goal is bracket arbitrage, not conversion for conversion's sake.
- Ignoring state taxes. Many states don't tax Social Security or pensions but do fully tax IRA withdrawals. Some states have no income tax at all. The optimal sequence is different in Florida than it is in California, and the numbers can shift substantially once the state layer is included.
- Forgetting about QCDs. Qualified Charitable Distributions from a traditional IRA after age 70½ satisfy RMDs without counting as taxable income. For charitably inclined retirees, QCDs should be the first RMD dollars spent — but only if they're actively planned into the sequence.
- Setting the plan and walking away. The optimal sequence depends on market returns, inflation, spending, tax law, and IRMAA thresholds — all of which move every year. A sequencing plan that isn't revisited annually is a plan that was right once and will get steadily less right.
Tax Law Changes Everything
Every sequencing analysis is built on the current tax brackets, standard deduction, IRMAA thresholds, and RMD rules. The lower brackets created by the Tax Cuts and Jobs Act are scheduled to sunset after 2025. Under current law, the 12% bracket reverts to 15% and the 22% bracket to 25% in 2026 and beyond. That single change shifts the math toward doing conversions and bracket-filling sooner — while today's lower rates are still available. Every year a client delays is a year of bracket space they can't get back.
Why This Matters for Advisors
Withdrawal sequencing is one of the highest-value services an advisor can deliver — and one of the hardest to sell without a visual. Clients don't intuitively accept the idea of paying more taxes today to save taxes later, and they certainly don't feel the $150,000 of lifetime IRMAA and tax savings that a well-designed sequence quietly produces. The conversation changes completely when you can show a side-by-side projection: same portfolio, same spending, two sequences, measurably different outcomes. At that point the recommendation sells itself.
How RetirementForge Helps
RetirementForge's Strategy Lab lets advisors model multiple withdrawal sequences side by side — showing clients the cumulative tax impact, bracket exposure, IRMAA risk, and Roth balance across their full retirement horizon. Combined with the Roth Conversion Analyzer and the RMD Calculator, advisors can build and present a year-by-year drawdown strategy in a single client session. Get started free and run your first sequencing analysis in minutes.
This article is for educational purposes only and does not constitute financial, tax, or legal advice. Tax laws, IRMAA thresholds, and RMD rules change regularly. Consult a qualified financial advisor and tax professional for guidance specific to your situation.