Meet the Roth Conversion Ladder: Turning a Tax Time Bomb into Tax-Free Wealth

Every dollar in a Traditional IRA is a dollar you haven't paid taxes on yet. That's not a problem when you're 40 and retirement is decades away. But at 73, when Required Minimum Distributions kick in, a large Traditional IRA can become a tax problem — pushing you into higher brackets and increasing your Medicare premiums (IRMAA).

A Roth conversion ladder lets you systematically move money from Traditional to Roth during lower-income years — paying taxes at today's rate to avoid higher rates later.

How Conversions Work

You transfer a portion of your Traditional IRA to your Roth IRA. You pay ordinary income tax on the converted amount in the year of conversion. After 5 years (or age 59.5, whichever comes first), those converted funds can be withdrawn tax-free.

What the Tool Models

The microtool takes your age, Traditional balance, Roth balance, annual income, filing status, years to convert, and any annual conversion cap — then builds a year-by-year ladder:

• Tax bracket impact: How each conversion fills your current tax brackets. The tool avoids pushing you into a higher bracket unnecessarily.
• Remaining Traditional balance: How much is left after each year of the ladder
• RMD impact: What your RMDs would have looked like without conversions vs. after the ladder
• Total tax cost: The cumulative taxes paid across the conversion period vs. the taxes that would have been paid on RMDs

The Key Insight: Fill, Don't Break, Your Bracket

The tool's smartest feature is bracket management: it calculates how much you can convert each year without crossing into the next tax bracket. If you're in the 22% bracket, it fills that bracket with conversions up to the threshold — then stops. The next dollar converted would be taxed at 24%, which might not make sense if your future RMDs would only push you to 22%.

Real Numbers: A $500K Traditional IRA at Age 50

• Current age: 50
• Traditional IRA: $500,000
• Current Roth: $100,000
• Annual income: $120,000 (22% bracket)
• Filing status: Single
• Years to convert: 15 (spread from 50 to 65)
• Conversion cap: $30,000/year (to stay in 22% bracket)

At $30K/year for 15 years: $450,000 converted, $99,000 in taxes paid (at 22%). The remaining $50,000 plus growth stays in Traditional. RMDs on the reduced Traditional balance are significantly smaller — and at age 73, you're no longer being pushed into the 24% or 32% bracket by forced withdrawals.

Without conversions: The $500K grows to roughly $1.4M by age 73 (at 7% growth). First-year RMD: approximately $53,000. Combined with Social Security and any other income, this could push you into the 24% bracket or trigger IRMAA surcharges.

The tool shows: A systematic conversion strategy over 15 years saves roughly $45,000–$65,000 in total lifetime taxes compared to doing nothing — and keeps Medicare premiums lower by avoiding IRMAA thresholds.

Why Most People Don't Do This

Roth conversions are complicated. They require forecasting your tax brackets, RMDs, and retirement income years in advance. Most tax preparers look backward, not forward. Most financial advisors don't proactively model conversion ladders because they don't generate fees — and getting it wrong creates an angry client.

Alistair does the multi-year modeling for you, year by year, bracket by bracket. You see exactly how much to convert, when, and what it costs — and what it saves.

That's what this microtool does. Build your ladder before the tax bill arrives.