Roth Conversion Ladder Planner

The bracket-filling strategy is the core optimization behind an effective Roth conversion ladder. Instead of converting a fixed dollar amount each year, you convert exactly enough to fill up to the top of a target tax bracket without spilling into the next one.

How it works step by step:

• Start with your other income — Add up Social Security (if any), pension, rental income, part-time work, and any other taxable income you expect that year.
• Subtract the standard deduction — For 2024, that is $14,600 (single) or $29,200 (married filing jointly). This gives you your taxable income before any conversion.
• Choose a target bracket — Most planners target the top of the 22% bracket ($100,525 single / $201,050 MFJ in 2024) as the sweet spot. Some aggressive planners fill into the 24% bracket if it is still well below their expected future rate.
• Convert the difference — The amount you convert equals the gap between your current taxable income and the top of the target bracket. For example, a married couple with $30,000 in other income and a $29,200 standard deduction has $800 in taxable income. They can convert up to $200,250 ($201,050 minus $800) and stay in the 22% bracket.

Why this matters: Progressive tax brackets mean that the first dollars converted are taxed at 10%, the next chunk at 12%, and so on. By never crossing into a higher bracket, you keep the blended effective tax rate on your conversions as low as possible. The calculator automatically calculates the optimal bracket-filling amount based on your inputs.

Common pitfall: Many people forget to account for state income taxes, ACA premium impacts, and IRMAA thresholds when choosing their target. The 22% federal bracket ceiling is a starting guideline, not a universal answer.

IRMAA (Income-Related Monthly Adjustment Amount) is a Medicare surcharge that increases your Part B and Part D premiums when your Modified Adjusted Gross Income (MAGI) exceeds certain thresholds. It is one of the most commonly overlooked costs in Roth conversion planning.

2024 IRMAA thresholds and surcharges:

• $103,000 (single) / $206,000 (married) — Base premium, no surcharge
• $103,001-$129,000 / $206,001-$258,000 — Additional $69.90/month per person for Part B
• $129,001-$161,000 / $258,001-$322,000 — Additional $174.70/month per person
• $161,001-$193,000 / $322,001-$386,000 — Additional $279.50/month per person
• Above $500,000 / $750,000 — Maximum surcharge of $384.30/month per person

Critical detail: The 2-year lookback. IRMAA is based on your MAGI from two years prior. A large Roth conversion in 2024 affects your Medicare premiums in 2026. This means you need to plan conversions with a 2-year forward view of when you will be on Medicare.

How this affects ladder planning: If you are 63 and planning conversions, you need to be aware that your age-63 conversion will impact your age-65 Medicare premiums. The bracket-filling strategy shown in this calculator targets the 22% bracket, which generally keeps MAGI below the first IRMAA threshold for married filers. However, single filers need to be more careful, as the single IRMAA threshold is only $103,000.

Pro tip: If a conversion would push you just $1 over an IRMAA cliff, it can cost $838+/year in extra premiums per person. It is sometimes worth converting slightly less to stay just under the threshold.

For early retirees between age 50 and 65 who are not yet on Medicare, Affordable Care Act (ACA) marketplace health insurance is often the primary coverage option. ACA premium tax credits are based on your Modified Adjusted Gross Income (MAGI), and Roth conversions count as income — which can dramatically reduce or eliminate your subsidies.

How ACA subsidies work:

• Premium cap percentage — Under current ACA rules, your required contribution to a Silver benchmark plan is capped at a percentage of your income. At 150% FPL, that cap is about 4% of income. At 400% FPL, it is about 8.5%.
• The subsidy cliff (before 2021 changes) — Historically, exceeding 400% of the Federal Poverty Level meant losing ALL subsidies. The enhanced ACA subsidies (currently extended through 2025) eliminated this cliff, but higher income still means substantially smaller credits.
• The MAGI impact — A $50,000 Roth conversion is added directly to your MAGI. For a couple with $20,000 in other income, a $50,000 conversion bumps MAGI from $20,000 to $70,000, potentially reducing their ACA subsidy by $3,000-$8,000+ per year depending on their state and plan.

Balancing the trade-off: The tax savings from a low-bracket Roth conversion must outweigh the lost ACA subsidies. For some early retirees, converting just enough to stay at a MAGI that preserves maximum subsidies (often around 200-250% FPL) is the optimal strategy, even if it means converting less than the full 22% bracket allows.

Strategy: Run the numbers both ways. Calculate your conversion tax savings at the full bracket-fill amount, then subtract the lost ACA subsidies. Sometimes smaller conversions over more years produce a better after-subsidy outcome than aggressive bracket-filling.

If you leave your Traditional IRA untouched from early retirement until RMD age, compound growth will significantly increase the balance — and with it, your future required minimum distributions and the taxes owed on them. This is sometimes called the RMD tax bomb.

An example scenario:

• Starting balance — $500,000 at age 45
• Growth rate — 7% nominal
• Balance at age 73 — Approximately $3.38 million (28 years of 7% growth)
• First RMD at 73 — $3,380,000 / 26.5 = $127,547/year, all taxable as ordinary income
• Tax on that RMD — For a married couple with $30K in Social Security, the RMD alone could push them into the 24% bracket, resulting in roughly $22,000+ in federal tax on the RMD
• IRMAA impact — That income level triggers the second or third IRMAA tier, adding $2,000-$4,000/year in Medicare surcharges per person

With a conversion ladder: If you had converted roughly $170K/year over 28 years (filling the 22% bracket), you would have moved a significant portion to a Roth at blended rates of 12-18%, leaving a much smaller Traditional IRA. Your RMDs would be drastically lower, keeping you in a lower bracket and potentially avoiding IRMAA entirely.

The bottom line: Doing nothing is itself a tax strategy — just usually a bad one. You are choosing to defer all tax to a future when your balance is larger and your RMDs force you into higher brackets. The conversion ladder gives you control over when and how much tax you pay.

The 5-year rule for Roth conversions is a key consideration for early retirees who may need to access converted funds before age 59.5. Each conversion has its own independent 5-year holding period.

The rule: If you withdraw the principal amount of a Roth conversion before it has been in the Roth for 5 tax years AND you are under age 59.5, you owe a 10% early withdrawal penalty on the amount. You do not owe additional income tax because you already paid that at the time of conversion.

How it applies to ladders:

• Year 1 conversion (age 45) — Must wait until tax year 6 (age 50) to withdraw penalty-free
• Year 2 conversion (age 46) — Must wait until age 51
• Year 5 conversion (age 49) — Must wait until age 54
• Year 6+ (age 50+) — The first rung is now accessible, and each subsequent year unlocks another rung

Bridge funding: During the initial 5-year waiting period, early retirees typically live off: (1) taxable brokerage accounts, (2) Roth IRA contribution basis (which can always be withdrawn tax and penalty-free), (3) cash reserves, or (4) 72(t) SEPP distributions. This is why financial planners recommend having 5 years of living expenses outside of retirement accounts before starting a conversion ladder.

Important nuance: The 5-year clock starts on January 1 of the tax year you convert. A December 2024 conversion has a clock starting January 1, 2024, so it becomes available January 1, 2029 — slightly less than 5 actual years of waiting.

Your filing status has a massive impact on how much you can convert at low tax rates because it determines your standard deduction amount and the width of each tax bracket. Married filing jointly (MFJ) has the widest brackets and largest deduction, providing the most room for tax-efficient conversions.

2024 standard deductions:

• Single — $14,600 standard deduction. The 22% bracket tops out at $100,525 in taxable income, meaning you can have up to $115,125 in total income and stay in the 22% bracket.
• Married Filing Jointly — $29,200 standard deduction. The 22% bracket tops out at $201,050 in taxable income, meaning up to $230,250 in total income stays in the 22% bracket. This is nearly double the single limit.
• Age 65+ bonus — An additional $1,550 per person (single) or $1,550 per spouse (married) is added to the standard deduction once you turn 65. This slightly increases your conversion room.

Strategic implications: A married couple with $10,000 in other income can convert approximately $191,050 per year and stay entirely within the 22% bracket ($10,000 + conversion - $29,200 deduction = $201,050 target). A single filer with the same $10,000 can only convert about $90,525 at the same bracket ceiling. This means married couples can execute faster, more aggressive conversion ladders.

For married couples considering divorce or separation: This is obviously not a tax strategy, but be aware that a change in filing status from MFJ to Single dramatically reduces your conversion capacity and shifts all bracket thresholds. If a status change is anticipated, front- loading conversions while still MFJ may be advantageous.

The answer depends on your IRA balance, time horizon, other income, and how aggressively you want to minimize future RMDs. In most cases, partial conversion (converting enough to fill low brackets each year) produces the best risk-adjusted outcome.

Case for partial (bracket-filling) conversion:

• Lowest blended tax rate — By converting only up to the 22% bracket, your effective rate on conversions stays around 12-18% depending on your other income and deductions
• Preserves ACA subsidies — Keeping MAGI moderate protects health insurance premium credits
• Avoids IRMAA — Staying under $206,000 MAGI (married) prevents Medicare surcharges
• Flexibility — You can adjust each year based on market returns, tax law changes, and personal circumstances

Case for aggressive (full) conversion:

• Very large balances — If your IRA is $2M+, even 28 years of bracket-filling may not convert enough to meaningfully reduce RMDs
• Tax rate expectations — If you believe future tax rates will be significantly higher (e.g., TCJA sunsets in 2026), paying 24% now may beat 28%+ later
• Estate planning — Converting everything means heirs receive tax-free Roth distributions instead of taxable Traditional IRA distributions under the 10-year rule
• Short conversion window — If you are 65 and RMDs start at 73, you only have 8 years. Aggressive conversion may be necessary to make a dent

The math: Use this calculator to compare outcomes. The bracket-filling approach shown here is the default strategy because it optimizes the tax rate on each dollar converted. But if your IRA balance is large relative to your conversion window, you may want to manually evaluate converting into the 24% bracket as well.

Social Security benefits become partially taxable when your "combined income" (AGI + nontaxable interest + half of Social Security benefits) exceeds certain thresholds. Roth conversions increase your AGI, which can trigger or increase the taxation of your Social Security benefits.

Social Security taxation thresholds:

• Below $25,000 (single) / $32,000 (married) — Social Security is not taxed
• $25,000-$34,000 / $32,000-$44,000 — Up to 50% of benefits are taxable
• Above $34,000 (single) / $44,000 (married) — Up to 85% of benefits are taxable

Why this matters for ladder planning: If you are doing conversions before Social Security starts (say, ages 45-62), there is no interaction because you have no SS income yet. This is another reason the early retirement gap years are the ideal conversion window.

However, if you are 62+ and have started Social Security while also doing conversions, each dollar of conversion increases your AGI, potentially making more of your SS taxable. In the worst case, an additional $1 of conversion income can create $1.85 of taxable income ($1.00 from the conversion + $0.85 of newly-taxable Social Security). This amplifies your marginal tax rate.

Best practice: Complete the bulk of your Roth conversion ladder before claiming Social Security if possible. Delaying SS to age 70 gives you both a higher benefit and more years of low-income conversions. This is one of the most powerful combinations in retirement tax planning.

The SECURE 2.0 Act (signed into law December 2022) made several changes that directly impact Roth conversion ladder planning, most notably by pushing back the age at which Required Minimum Distributions must begin.

Key RMD changes:

• Born 1951-1959 — RMDs start at age 73
• Born 1960 or later — RMDs start at age 75
• Roth 401(k) RMDs eliminated — Starting in 2024, Roth 401(k) accounts are no longer subject to RMDs during the owner's lifetime (previously they were, unlike Roth IRAs)
• Reduced RMD penalty — The penalty for missing an RMD dropped from 50% to 25%, and to 10% if corrected within 2 years

Impact on conversion ladder planning: The later RMD start ages (73-75) give early retirees more years to execute conversion ladders. Someone retiring at 45 now has 28-30 years of potential conversion years instead of the previous 25.5 years (when RMDs started at 70.5). More years means you can convert more gradually, staying in lower brackets each year.

Other SECURE 2.0 provisions affecting conversions:

• 529-to-Roth rollovers — Starting 2024, up to $35,000 lifetime can be rolled from a 529 plan to a Roth IRA for the beneficiary (subject to annual contribution limits and 15-year account age requirement)
• Employer Roth matching — Employers can now contribute matching funds directly to a Roth 401(k), which means more money already in Roth status
• Catch-up contribution Roth requirement — Starting 2026, workers earning over $145,000 must make catch-up contributions on a Roth basis only

This calculator uses the SECURE 2.0 RMD ages and the updated Uniform Lifetime Table for distribution factor calculations.