Write four numbers before you pick a bucket. (1) This year’s cash spend after pensions you already have. (2) Taxable brokerage: cost basis vs unrealized long-term gain, lot by lot — specific identification, not FIFO. (3) Traditional IRA / 401(k) balance. (4) Roth IRA / Roth 401(k) balance. Add the HYSA sleeve you will not raid for a conversion tax. If you cannot name the four, you are guessing. Asset-location is a different file: where the funds sit. This file is the order you take dollars out.
Write the calendar: Medicare, Social Security, RMD age. Born 1951–1959: RMDs start at 73. Born 1960 or later: 75 (SECURE 2.0; IRS Pub. 590-B). First RMD can wait until April 1 of the following year — that is a two-RMD calendar year, which is how people walk into IRMAA by accident. Medicare is 65. Social Security is a claiming choice, not a tax strategy — the household file is couples claiming. Gap years are the seasons between a paycheck stopping and those three clocks. Count them. Nine empty years is not the same file as two.
Spend cash above the sleeve. Do not empty the emergency fund because a blog said “taxable first.” Cash that is the next 3–12 months of spend is not a tax lot. “Taxable first” means brokerage lots, not the HYSA that keeps a water heater off a 24% card. Park-the-cash mechanics stay in I-bonds vs T-bills vs HYSA. If the sleeve would go to $0 to harvest a 0% gain, you wanted the gain next year.
Harvest long-term lots at 0% while ordinary income is still low. 2026 0% long-term band (Rev. Proc. 2025-32): taxable income up to $49,450 single / $98,900 MFJ / $66,200 HOH. Ordinary income fills first; LTCG stacks on top. Specific-ID the lots. Qualified dividends sit in the same 0/15/20 stack. 15% LTCG runs to $545,500 single / $613,700 MFJ; 20% after that. NIIT 3.8% still starts at MAGI $200,000 single / $250,000 MFJ (not indexed). Short-term lots are ordinary income — do not “harvest” a 5-month lot into the 12% fill. Primer: short vs long. Numbers: capital-gains calculator. Losses are the harvest file, not this one.
Fill remaining 12% (sometimes 22%) with traditional withdrawals for spend, or Roth conversions. 2026 ordinary: 12% ends at taxable $50,400 single / $100,800 MFJ; 22% ends at $105,700 / $211,400; standard deduction $16,100 / $32,200 / $24,150 HOH (Rev. Proc. 2025-32 / IR-2025-103). Age-65 extra standard deduction is $2,050 unmarried / $1,650 per spouse — separate from any temporary senior deduction. Pay conversion tax from taxable cash, not from the IRA. Converting and withholding from the IRA is how a $91k conversion becomes a smaller Roth and a MAGI spike. Primer: who conversions actually help. Filling 12% on purpose beats minimizing this year’s tax to $0 and exploding at RMD age.
IRMAA is a two-year MAGI cliff, not a bracket. 2026 Part B standard premium is $202.90/mo. First surcharge (2024 MAGI above $109,000 single / $218,000 MFJ): Part B $284.10 + Part D $14.50 — $95.70/mo extra per person, $2,297/yr for a couple (CMS Nov 14, 2025 fact sheet; SSA POMS HI 01101.020). Next cliff ($137k / $274k) is $405.80 Part B + $37.50 Part D. Cross by a dollar, pay the tier all year. 2026 MAGI sets 2028 premiums. Run the year through IRMAA MAGI room before you convert. Work-stoppage can justify SSA-44; a stock sale cannot. Sequence: IRMAA planning — do not rebuild it here.
Before 65, ACA MAGI is the subsidy. Roth and basis can keep MAGI down; traditional cannot. Premium tax credits use MAGI this year, not two years from now. Filling the 12% bracket with conversions in an ACA year can cost more in lost PTC than it saves in future RMDs. That year, spend from Roth contributions / converted basis (after the conversion 5-year clock if you are under 59½) or from brokerage basis, and convert less. The slogan “Roth last” is how people light a subsidy. After Medicare starts, this cliff dies and IRMAA takes its place — same MAGI, different bill.
Convert before Social Security when the calendar allows. Provisional income = AGI + tax-exempt interest + 50% of Social Security. Thresholds are not indexed: 50% of benefits taxable above $25,000 single / $32,000 MFJ; 85% above $34,000 / $44,000 (IRC 86). Traditional withdrawals and conversions sit in AGI and pull more of the benefit into the 85% band — the “tax torpedo.” A gap-year conversion that never meets a benefit is often cheaper than the same conversion at 70 sitting next to a delayed credit. Claiming itself is still the household file: delay the high earner; do not claim early to “fill a bracket.”
Treat RMDs as a design constraint, not a December surprise. Formula: prior year-end balance ÷ Uniform Lifetime Table factor (Treas. Reg. §1.401(a)(9)-9). Age 73 factor 26.5; age 75 24.6. Worked: $800,000 traditional, 7% for 11 years to age 75 → $1,683,882 ÷ 24.6 ≈ $68,450 that must come out, ordinary income, whether you needed it or not. Missed-RMD penalty is 25%, 10% if corrected in the window (SECURE 2.0). Roth IRAs have no lifetime RMD for the original owner. Run today’s balance through the RMD calculator. The paid RMD sequence (QCDs, inherited 10-year, April 1 trap) is ira-rmd-playbook — cross-link, do not copy it.
If you give anyway and you are 70½, QCD before you write a check from the brokerage. 2026 QCD cap is $111,000 per IRA owner (IRS Notice 2025-67; $108,000 was 2025). Trustee-to-charity, not a check you deposit first. A QCD can satisfy that year’s RMD and does not land in AGI the way a normal withdrawal does — which is why it is an IRMAA tool. You cannot also deduct it on Schedule A. One-time split-interest election is $55,000 inside the annual cap, not on top. Deadline is December 31, no extension. If you do not give, skip this step; do not invent a charity to dodge MAGI.
“Roth last” is the default except three years. Leave most Roth for (a) a year you must hold MAGI down — IRMAA, ACA, NIIT, or the 0% LTCG band you are trying to keep, (b) late years when RMDs plus Social Security already fill 22%/24%, (c) heirs under the 10-year inherited-IRA rule, who would rather inherit Roth. HSA after 65 is a medical Roth: qualified medical is tax-free; non-medical is ordinary income like a traditional IRA. Spending Roth contributions is not a MAGI event. Spending a current-year conversion under 59½ can be a 10% problem — each conversion has its own 5-year clock. After 59½ the conversion principal is clean; earnings still need the account to be 5 years old.
Hard-stop list: converting on a credit card; withholding the conversion tax from the IRA; dumping $250k into Roth in one year to “get it over with” and lighting IRMAA at $274k MFJ ($5,770/yr extra Part B+D for a couple at the 2026 second cliff); taking Roth to drive MAGI to $0 and then exploding at the first RMD; FIFO lots when specific-ID would have been 0%; treating the Sep 2026 0% band as a 2027 number; missing the Dec 31 RMD/QCD; delaying the first RMD to April 1 without counting the double year; claiming Social Security early so you can “afford” a conversion; skipping the 401(k) match in a still-working year to fund a conversion (match first — order of operations). If the MAGI tool says you are $2,000 under a cliff, you wanted a smaller conversion, not a bigger slogan.
One-page decision
Sleeve stays. Taxable lots at 0% while ordinary is low. Fill leftover 12% with traditional-for-spend or conversions paid from cash. Run MAGI through the IRMAA calculator every conversion year — 2026 MAGI is 2028 Part B. ACA years: convert less, spend Roth/basis. Convert before Social Security when you can. Grow-forward the traditional pile in the RMD tool so age 73/75 is a number, not a feeling. QCD only if you give. Roth last except MAGI-control years, late RMD years, and heirs. Nobody is required to convert; nobody is required to leave a $1.7M traditional IRA for a $68k RMD.
Worked example (educational, not advice): MFJ, both 64, $80,000 spend, no Social Security yet, 2026. Harvest $40,000 LTCG + $40,000 basis from brokerage (spend). Convert $91,100 traditional → Roth. Ordinary taxable $58,900 after the $32,200 standard deduction; stacked with the gain = $98,900 (exactly the 0% LTCG cap). Federal tax on the conversion year ≈ $6,572 (10% of $24,800 + 12% of $34,100); LTCG at 0%. MAGI ≈ $131,100 — under the 2026 IRMAA first cliff of $218,000 MFJ. Same $80k from the IRA instead: tax ≈ $5,240, but the $40k 0% lot sits unused and the traditional pile is untouched. Leave $800,000 traditional alone at 7% to age 75: RMD ≈ $68,450 (factor 24.6).