[TX-03] Withdrawal-Order Sequencing

Why “Taxable → Traditional → Roth” Is Often Wrong, and What to Do Instead

Pillar: Tax Optimization & Decumulation · Applies to: Everyone drawing down a multi-account portfolio Last verified: August 2026 · Refresh cadence: Annual (figures via FN-02) Related: FN-02 Key Numbers · ER-02 Roth Ladder · HC-01 ACA Bridge · HC-06 IRMAA · TX-01 0% Capital Gains · TX-02 Roth Conversion Strategy · SS-03 SS Taxation · EP-01 Beneficiary Hygiene

Not advice. Sequencing decisions compound over 30+ years and interact with health subsidies, Medicare surcharges, and your heirs’ tax rates. Model your own numbers.

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TL;DR

• The classic advice — drain taxable, then traditional, then Roth — maximizes deferral, not after-tax wealth. It wastes your low-bracket years early, then detonates an RMD tax bomb at 73–75.
• The better default is “fill and spill”: every single year, deliberately fill the low tax brackets with ordinary income from traditional accounts (withdrawals or conversions), spill the rest of your spending from taxable (harvesting 0% capital gains where possible), and preserve Roth for high-bracket years, late-life spending, and heirs.
• Your target “fill line” changes by life phase: the ACA line before 65 (HC-01), the IRMAA/bracket line from 65 to RMDs, and the QCD-first playbook after RMDs begin.
• Sequencing is also an estate decision: taxable assets get a basis step-up at death, Roth is the best asset to inherit, and traditional is the worst — heirs get a 10-year drain order at their own peak-career rates.
• The commonly cited payoff of getting this right is meaningful: studies of tax-aware sequencing consistently find portfolio-longevity gains on the order of one to three extra years of spending versus naive ordering — without changing investments at all.

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1. The Three Buckets and Their Physics

	Taxable brokerage	Traditional IRA/401(k)	Roth
Withdrawals taxed as	Only the gain, at LTCG rates (0/15/20%)	100% ordinary income	0%
Annual drag	Dividends/interest taxed yearly	None	None
Forced distributions	None	RMDs at 73/75	None (owner)
MAGI impact per $ spent	Low (gain portion only)	Full	Zero
At your death	Basis step-up — gain erased	Heirs pay ordinary tax, 10-year drain	Heirs drain in 10 yrs, tax-free
Best use	Bridge fuel, 0%-gain harvesting, die holding winners	Fill low brackets every year; charity	High-bracket years, late-life, legacy

Two properties drive everything: traditional dollars are pre-tax IOUs to the IRS at an unknown future rate, and taxable dollars carry an erasable tax liability (step-up). Roth dollars are done arguing with the IRS.

2. Why the Conventional Ladder Fails

Picture the standard advice applied to a 62-year-old couple with $1.5M traditional, $700k taxable, $300k Roth, spending $100k:

1. Years 62–70: they live on taxable. Realized gains are modest, so their taxable income is near zero — and the standard deduction ($32,200 MFJ, more at 65+) plus the 10% and 12% brackets go unused, every year. That’s ~$130k/year of 0–12% capacity evaporating.
2. Year 70–73: taxable is exhausted; Social Security starts; then RMDs on a traditional account that grew untouched to ~$2.3M force ~$90k+ of ordinary income on top of SS — parking them in the 22–24% brackets for life, triggering IRMAA tiers (HC-06) and maximum SS taxation (SS-03).
3. First death: the survivor inherits the same income stream but files single — same money, compressed brackets, higher IRMAA thresholds crossed. The widow(er)’s penalty is a sequencing failure booked decades earlier.

Deferral felt free. It was a loan at an unknown rate, and the rate came in high.

3. The Better Default: Fill and Spill

Each year, in this order:

1. Take what’s forced: RMDs (if 73+), pensions, annuity payments, Social Security. This income is your floor.
2. Choose a fill line for ordinary income — the top of a bracket, an ACA FPL line, an IRMAA threshold, or the standard-deduction line — based on your phase (§4).
3. Fill to the line with traditional-account dollars: withdrawals if you need the cash, Roth conversions if you don’t (ER-02/TX-02). Either way, the low-bracket space gets used.
4. Spill the remaining spending need from taxable — preferring lots that realize gains inside the 0% LTCG bracket ($98,900 MFJ taxable income in 2026), remembering conversions stack under gains and compete for that space (ER-02 Layer 3).
5. Touch Roth last — but not never: Roth is the pressure-relief valve for any year that would otherwise cross a cliff (ACA 400% FPL, an IRMAA tier, the 32% bracket, a child’s FAFSA base year).

The result is a deliberately flat lifetime tax rate — many moderate years instead of a decade of 0% followed by decades of 24%+.

4. The Fill Line by Phase

Phase 1 — Retirement to 65 (the ACA years). The binding constraint is usually MAGI, not brackets. Run the HC-01 lane strategy: subsidy years fill only to an FPL line (150/200/250/399%); designated conversion years fill a real bracket and forgo subsidy. Spending comes disproportionately from taxable basis and cash; the “fill” is mostly conversions, not withdrawals.

Phase 2 — 65 to RMDs (the golden window). ACA constraint gone; RMDs and (ideally) Social Security not yet started — this is the cheapest ordinary income of your life. Fill aggressively: many households should run to the top of the 12% bracket at minimum, and to the top of the 22% (or even 24%) when the traditional balance is large, because the alternative is those same dollars emerging later at 22–24%+ plus IRMAA plus survivor-bracket risk. Watch three lines: IRMAA tiers from age 63 onward (2-year lookback — $109k/$218k first cliff in 2026), the senior-deduction phase-out at $75k/$150k MAGI through 2028 (which lifts the effective marginal rate by ~1.3–2.9 points inside the band, not by 6 — TX-02 §5), and SS-claiming timing — delaying SS to 70 widens this window, a chronically underrated argument for delay.

Phase 3 — RMD era. The forced floor is set; your levers shrink to: QCDs first for any charitable intent ($111k/person in 2026 — pre-tax dollars to charity at a 0% rate, satisfying the RMD, TX-04); marginal spending beyond RMD+SS from taxable (still step-up-eligible) before Roth; Roth for spikes (a roof, a car, LTC premiums) that would otherwise jump a bracket or IRMAA tier.

5. The Estate Overlay (Who Gets Which Bucket)

Sequencing while alive determines what your heirs inherit:

• Traditional → charity. Via QCDs while living and charitable beneficiary designations at death, pre-tax money is the only asset a charity receives at full value and heirs receive at a discount. If you’re charitable at all, spend traditional down last for bequests but first for giving.
• Taxable → hold winners to death. The step-up erases embedded gains; in community-property states (WA included) both halves step up at the first death — a mid-marriage rebasing most couples never use. Don’t harvest large gains at 15/20% in your 80s that death would have erased.
• Roth → the kids. Ten more years of tax-free growth in their hands, no income stacked onto their peak earning years. Every conversion you make is partly a gift to their marginal rate.
• Inherited traditional is the booby prize: the 10-year rule with annual RMDs (when you’d started yours) lands on children in their 50s at their career-peak brackets — often the strongest single argument for converting more than your own lifetime math suggests.

6. Worked Example: The Same Couple, Resequenced

Couple, both 62, retiring now, Washington residents — no state income tax, so every figure below is federal-only (ST-04 §1.1). Traditional IRA $1,500,000 · taxable $700,000 (basis $500,000) · Roth $300,000. Spending $100,000/yr. Their taxable account throws off about $20,000 of qualified dividends whether they want it or not.

Phase 1 — ages 62–64, on the exchange

Target MAGI: 245% FPL = $51,818 for a household of two (FN-02). Dividends supply $20,000 of it, so the conversion is sized to fill the rest.

	Amount
Qualified dividends (unavoidable)	$20,000
Roth conversion	$31,818
Total income / ACA MAGI	$51,818
Less standard deduction (both under 65)	($32,200)
Taxable income	$19,618 — entirely qualified dividends, inside the 0% LTCG band
Federal tax	$0 ✅

They convert $31,818 a year at a zero federal rate while holding a subsidized Silver plan, funding the $100,000 of spending from taxable basis and cash — neither of which creates MAGI (HC-01 §5).

Phase 2 — ages 65–69, the golden window

Medicare starts, the ACA constraint disappears, and Social Security is deferred to 70 (SS-01). Now fill the 22% bracket to its top.

	Amount
Qualified dividends	$20,000
Roth conversion	$226,900
Total income / IRMAA MAGI	$246,900
Less standard deduction (both 65+)	($35,500)
Taxable income	$211,400 — exactly the top of the 22% band
Federal income tax	$34,532
IRMAA (tier 1, couple, one year)	$2,297
Total federal cost	$36,829
Effective rate on the conversion	16.2%

Read the last line twice. Filling the 22% bracket to its top costs an effective 16.2%, not 22% — the standard deduction and the 10/12% bands absorb the first $136,300 of it. That number is what makes the golden window worth using aggressively, and it is invisible unless you compute it. They accept exactly one IRMAA tier on purpose and stop well below the $274,000 tier-2 line (HC-06 §3).

Eight years later

Ignoring portfolio growth for clarity: 3 × $31,818 + 5 × $226,900 ≈ $1,230,000 converted out of a $1.5M starting balance.

At age 73	Naive path (drain taxable, convert nothing)	Sequenced path
Traditional balance	~$2,200,000	~$400,000
First RMD (Uniform Lifetime factor 26.5 at age 73 ✅)	$83,019	$15,094

The naive path’s RMD alone nearly fills the 22% bracket before a dollar of Social Security is added, and it rises every year thereafter. The sequenced path’s is absorbed by the standard deduction and the 10% band. The gap then compounds into the survivor’s return, where the brackets halve (TX-02 §3).

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7. The December Procedure

This article is the traffic controller; the others hold the individual rules. Once a year, in December — after fund distributions post and the year’s income is knowable — work them in this order:

1. Tally what’s forced. RMDs, pensions, annuities, Social Security, dividends, capital-gain distributions. You don’t choose this; it’s the floor.
2. Find the binding constraint — the lowest ceiling that applies this year, not the most familiar one:

If you are…	The line that binds
Under 65 and subsidized	An FPL line (HC-01 §2)
Below the Medicaid/BHP floor	The floor, from underneath (HC-03 §7)
Age 63+	The next IRMAA tier (HC-06 §6)
Claiming Social Security	The far edge of the torpedo band (SS-03 §3)
None of the above	A bracket top (TX-02 §6)

3. Decide who owns the year: conversions or gain harvesting. They compete for the same bracket space, and running both costs about 27% on the overlap (TX-01 §5).
4. Fill to the line — withdrawal if you need the cash, conversion if you don’t.
5. Spill the remaining spending from taxable: 0%-bracket gains first, high-basis lots next.
6. Use Roth only to duck a cliff you’d otherwise cross.
7. Log the decision — amount, line chosen, reason.

One rule overrides the rest. If you are claiming Social Security and sitting inside the torpedo, check whether clearing the band is cheaper than stopping short of it (SS-03 §3). It is the one place in this entire system where converting more lowers your marginal rate, and step 2’s instinct — find the ceiling and stay under it — gets it exactly backwards.

8. Three Scenarios

A. The fat-balance couple (§6 above). Large traditional balance, long runway, no state tax. The framework says fill aggressively, and the arithmetic says filling the 22% bracket really costs 16.2%. They convert ~$1.23M across eight years and cut the first RMD from $83,019 to $15,094.

B. The couple who should stop filling (both 66, $420k traditional, $38k spending, SS at 70). Projected RMDs at 73 are roughly $16,000/year on top of $52,000 of Social Security — their taxable income never leaves the 12% bracket, in any year, including the survivor’s. Filling the 22% bracket here converts 12% money into 22% money. They fill only to the top of the 12% band, and in years they’d rather harvest gains they convert nothing at all (TX-01 §5). The framework does not always say “convert more” — it says “compare the rates,” and sometimes the comparison says stop.

C. The single filer with a pension (68, $60k pension, $28k Social Security, $600k traditional). His floor is high and non-discretionary, and single brackets are half a couple’s. Provisional income is already past the $34,000 single line ✅ — a threshold fixed in statute since 1993 and never indexed (SS-03) — so he is deep in the 85% band — and his marginal rate is the 22% bracket × 1.85 = 40.7% until he clears the torpedo (SS-03 §4). His binding constraint is not a bracket or an IRMAA tier; it is the torpedo, and the correct move is to convert through it rather than nibble under it. Nothing about his situation is visible from a bracket table alone.

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💡 Pro-Tips

1. Never file a return with an empty standard deduction in retirement — that’s a 0% bracket you paid taxes your whole life to earn.
2. Conversions count as “fill.” If spending doesn’t reach the line, convert the gap — the cash-flow and the tax decision are separable.
3. Delaying Social Security is a tax strategy, not just a longevity bet: it buys 5–8 extra golden-window years.
4. Recompute the fill line every December, not once at retirement — distributions, one-off income, and law changes move it annually.
5. Roth is a scalpel, not a default: deploy it to avoid crossing lines, and its value becomes visible and countable.
6. QCD before any cash charity once 70½ — a $10k QCD beats a $10k check even for standard-deduction filers.
7. Asset location amplifies sequencing: bonds in traditional (slows the tax bomb’s growth), high-growth equity in Roth, index equity in taxable (step-up candidate). → ER-06
8. Model the survivor scenario explicitly — run every plan through single-filer brackets at the older spouse’s mortality age.

⚠️ Common Pitfalls

1. Running the naive ladder and discovering the RMD bomb at 72 — the fix window (the golden years) is behind you.
2. Bragging about $0 tax years in your early 60s. A $0 year usually means wasted brackets, not victory.
3. Filling brackets pre-65 while forgetting MAGI ≠ taxable income — the ACA and (later) IRMAA run on MAGI before the standard deduction.
4. Harvesting big gains in old age that step-up would have erased — especially costly in community-property states.
5. Leaving traditional IRAs to high-earning children while Roth goes to charity — exactly backwards.
6. Ignoring the widow(er)’s penalty until it’s the widow(er) doing the math.
7. Letting the 0%-LTCG bracket and conversions silently collide — one strategy owns each year’s space (ER-02 Layer 3).
8. Treating RMDs as the plan — they’re the failure mode the plan exists to shrink.
9. One-time sequencing decisions. This is an annual control loop, not a set-and-forget order.

✅ Actionable Checklist

Once (design)

• Inventory the three buckets: balances, taxable-account basis, traditional/Roth split
• Project RMDs at 73/75 on a “do nothing” path — size the bomb
• Run the survivor scenario (single brackets, one SS check)
• Set the estate map: charity ← traditional · heirs ← Roth · step-up ← taxable winners
• Choose phase-1/2/3 fill lines and write them down

Every year (the December loop)

• Tally forced/unavoidable income (RMD, SS, pensions, dividends, distributions)
• Confirm this year’s line (FPL / bracket / IRMAA / deduction) from FN-02
• Fill to the line: withdrawal for cash needs, conversion for the remainder
• Spill spending from taxable — 0%-bracket gains first, high-basis lots next
• Use Roth only to duck a cliff; log everything (a DECISIONS.md for your taxes)

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State notes (→ ST-01): No-income-tax states (WA, FL, TX, TN, NV, SD, WY, AK, NH) make “fill” dramatically cheaper — the golden-window conversion math improves by your would-be state rate, compounding for decades. States that exempt retirement income but tax wages (IL, PA, MS) flip which income to realize where. Community-property states double the step-up motive to hold taxable winners. And a state estate tax (WA: $3M exemption, frozen, up to 20%; OR: $1M) can argue for faster drawdown, lifetime gifting, or credit-shelter planning that the federal $15M exemption alone would never suggest.

Sources & further reading (verified Aug 2026)

• IRS Pub. 590-B (RMDs, inherited-IRA rules); FN-02 for all thresholds (Rev. Proc. 2025-32; QCD $111k)
• SECURE / SECURE 2.0 (RMD ages 73/75; 10-year rule); OBBBA (bracket permanence; senior-deduction phase-out)
• Research base: Cook, Meyer & Reichenstein, “Tax-Efficient Withdrawal Strategies” (Financial Analysts Journal); Vanguard and Morningstar decumulation research on sequencing alpha
• HC-01 §5 and ER-02 §4 for the pre-65 MAGI overlay; HC-06 for IRMAA tiers