The Roth Conversion Ladder is conceptually simple: convert Traditional IRA money to Roth, wait five years, withdraw tax-free. But how much you convert each year is the decision that determines whether this strategy saves you $50,000 or costs you $20,000 in unnecessary taxes.
Convert too little, and you leave low-bracket space unused — space you can never get back. Convert too much, and you spike into higher brackets, triggering unnecessary taxes and potentially wiping out your ACA health insurance subsidies.
Here's how to engineer the optimal conversion amount every year.
The Bracket-Fill Strategy
The core principle: each year, convert exactly enough to fill your target tax bracket to the top. This maximizes tax-free and low-tax space each year without spilling into higher brackets.
For most FIRE households, the 12% bracket is the sweet spot. Here's what that means in practice for 2026:
Single filer:
- Standard deduction: $16,100
- 12% bracket top: $50,400
- Total room: $50,400 + $16,100 = $66,500
- If you have no other income, you can convert $66,500 and pay roughly $4,700 in federal tax (an effective rate of about 7%, well below your working-years marginal rate)
Married filing jointly:
- Standard deduction: $32,200
- 12% bracket top: $100,800
- Total room: $100,800 + $32,200 = $133,000
- With no other income, a married couple can convert $133,000 and pay roughly $9,400 in federal tax (about 7% effective)
This is the magic of the bracket spread. A married couple gets twice the 12% bracket space of a single filer ($100,800 vs $50,400), and a larger standard deduction on top. If you expect to file jointly in retirement, the math tilts even more strongly toward Traditional contributions during your working years.
2026 Tax Brackets Reference
These are the confirmed 2026 brackets. Keep them bookmarked — you'll reference them every year during your ladder.
Single Filers
| Taxable Income Range | Marginal Rate |
|---|---|
| $0 – $12,400 | 10% |
| $12,401 – $50,400 | 12% |
| $50,401 – $105,700 | 22% |
| $105,701 – $201,775 | 24% |
| $201,776 – $256,225 | 32% |
| $256,226 – $640,600 | 35% |
| $640,601+ | 37% |
| Standard Deduction | $16,100 |
Married Filing Jointly
| Taxable Income Range | Marginal Rate |
|---|---|
| $0 – $24,800 | 10% |
| $24,801 – $100,800 | 12% |
| $100,801 – $211,400 | 22% |
| $211,401 – $403,550 | 24% |
| $403,551 – $512,450 | 32% |
| $512,451 – $768,700 | 35% |
| $768,701+ | 37% |
| Standard Deduction | $32,200 |
Long-Term Capital Gains (2026)
| Rate | Single | MFJ |
|---|---|---|
| 0% | $0 – $49,450 | $0 – $98,900 |
| 15% | $49,451 – $543,400 | $98,901 – $638,550 |
| 20% | $543,401+ | $638,551+ |
Combining Conversions with Capital Gains
Here's where it gets interesting. Roth conversions count as ordinary income and sit under capital gains in the tax stack. That means conversions push your capital gains into higher brackets.
Example: You're single, with $20,000 in long-term capital gains from selling taxable brokerage funds and a $50,000 Roth conversion.
- Conversion ($50,000) minus standard deduction ($16,100) = $33,900 taxable ordinary income
- The $20,000 LTCG sits on top, starting at $33,900
- Since $33,900 + $20,000 = $53,900, and the 0% LTCG bracket ends at $49,450, about $4,450 of your gains fall into the 15% bracket
- Result: $4,450 × 15% = $668 in capital gains tax you could have avoided
The fix: reduce your conversion by $4,450. You lose a small amount of conversion space but save $668 in unnecessary capital gains tax. This kind of bracket-micro-optimization is what separates a good ladder from a great one.
For married couples with up to $98,900 in the 0% LTCG bracket, there's much more room to harvest gains tax-free alongside conversions. The MFJ advantage shows up everywhere.
The ACA Subsidy Trap
If you're getting health insurance through the Affordable Care Act marketplace — and most early retirees do — your Roth conversion amount directly affects your premium tax credits.
ACA subsidies are based on Modified Adjusted Gross Income (MAGI). Roth conversions count as MAGI. If your conversion pushes your MAGI above 400% of the Federal Poverty Level (FPL), you lose subsidies entirely. For 2026, 400% FPL is roughly:
- $60,000 for a single person
- $81,000 for a couple
- $103,000 for a family of four
This creates a tension: you want to convert as much as possible to fill the 12% bracket ($66,500 single / $133,000 MFJ including deduction), but doing so may erase thousands in health insurance subsidies.
Run both scenarios. For a couple, converting $80,000 (staying under 400% FPL) might preserve $8,000 in annual subsidies while still achieving meaningful ladder progress. Converting $133,000 might save $3,000 in future taxes at the cost of $8,000 in current subsidies — a net loss.
The Roth Conversion Ladder Calculator models the subsidy interaction so you can find the right balance. For a deeper look at the complete strategy, read the pillar guide.
Social Security Timing
Roth conversions interact with Social Security in a specific and painful way. The more taxable income you have — including conversion income — the more of your Social Security benefit becomes taxable. At certain thresholds, up to 85% of your benefit can be taxed as ordinary income.
This creates a strategic window: convert aggressively in your early retirement years (before claiming Social Security), then reduce or stop conversions once benefits begin. The ideal window:
- Ages 60-70: Convert as much as possible while no Social Security income is in the picture
- Age 70: Claim Social Security for maximum delayed retirement credits
- Post-70: Zero or minimal conversions to avoid pushing Social Security into the taxable range
The payoff for this patience is substantial: delaying from 62 to 70 increases your monthly benefit by roughly 77% (8% per year). That's permanent, inflation-adjusted, and survivor-protected income.
State Tax Arbitrage
Federal taxes get most of the attention, but state taxes can swing the ladder math by 5-13% per year.
Zero income tax states (no tax on conversions): Florida, Texas, Nevada, Washington, Tennessee, New Hampshire, South Dakota, Wyoming, Alaska
Highest tax states (conversions fully taxed as income): California (up to 13.3%), New York (up to 10.9%), New Jersey (up to 10.75%), Oregon (up to 9.9%)
If you're planning to relocate from a high-tax state to a zero-tax state, there's a strong argument for delaying Roth conversions until after the move. A $100,000 conversion costs $0 in state tax in Florida and up to $9,300 in California. That's real money left on the table.
The flip side: if you're already in a zero-tax state and might move to a state with income tax later, convert more aggressively now while your state rate is zero.
The Multi-Year Strategy
Your conversion strategy should evolve across three phases:
Phase 1: Early Retirement (Pre-60)
This is the ladder's primary operating window. Convert enough to fill the 12% bracket while staying under ACA subsidy cliffs. If your expenses are $50,000 and you convert $50,000 per year, after 5 years you have a perpetual pipeline: each year's new conversion replaces the matured conversion you're now withdrawing.
This phase typically covers ages 40-60 and may involve 15-20 years of annual conversions. Small, consistent conversions compound into enormous tax savings.
Phase 2: Pre-RMD Years (60-72)
Once you hit 59½, penalty-free Traditional withdrawals are available. The ladder is no longer strictly necessary for access — but it still offers tax optimization value. Continue converting up to the top of the 12% bracket to reduce future RMDs.
This is also the prime window for larger conversions, since you're not yet drawing Social Security and may not yet be on Medicare (IRMAA surcharges kick in at certain income levels starting at 65).
Phase 3: Post-RMD (73+)
Required Minimum Distributions begin at 73. Any remaining Traditional balance will be forced out at whatever your tax bracket happens to be. The goal of the ladder strategy is to minimize the Traditional balance before RMDs begin — ideally, convert so much during Phases 1 and 2 that RMDs are small and manageable.
A $1 million Traditional IRA at age 73 produces a first-year RMD of roughly $37,700. That's fully taxable and may push Social Security into taxable territory. Convert aggressively in your 60s and early 70s to reduce that number.
Annual Conversion Checklist
At the start of each year, run through this:
- Calculate your target MAGI for the year (considering ACA subsidies)
- Subtract any other income: part-time work, dividends, interest, rental income
- The remainder is your conversion budget — fill the 12% bracket with it
- Verify your conversion doesn't push capital gains into the 15% bracket
- Check state tax implications (especially if planning a move)
- Execute the conversion early in the year for maximum tax-deferred growth inside the Roth
Run your specifics through the Roth Conversion Ladder Calculator for a year-by-year projection. For bridge funding strategy, see our bridge funding guide.
Tax bracket engineering isn't complicated — it's just deliberate. Know your brackets, fill them strategically, and let time do the rest.
Sources
- IRS Revenue Procedure 2025-36 — 2026 inflation-adjusted tax rate schedules and capital gains brackets
- IRS Publication 590-B — Distributions from IRAs, including Roth conversion rules
- Healthcare.gov — ACA premium tax credit income thresholds
- SSA Retirement Benefits — Delayed retirement credits and Social Security taxation