What a Roth conversion ladder is
A conversion ladder is a multi-year sequence of partial Roth conversions executed during the low-income window between retirement and Required Minimum Distributions. The ladder spreads the tax cost across years, keeps each year's marginal rate inside a chosen ceiling, and converts the largest possible balance before RMDs and Social Security start filling brackets involuntarily.
Sizing the runway
Three numbers define the ladder:
- Years available — typically retirement age through age 72 (or 74 for those born 1960+).
- Annual headroom — bracket capacity below the marginal-cost ceiling (federal + state + IRMAA + NIIT).
- Convertible balance — Traditional IRA, Rollover IRA, SEP, SIMPLE; not Roth, not HSA, not after-tax 401(k).
Annual cadence: when to execute
- January–February: draft the year's target conversion based on prior-year actuals.
- June: mid-year true-up; check market drawdowns (a 15%+ drop is a stronger conversion moment).
- October: finalize using known dividend, capital gain, and pension figures.
- Mid-December: execute. Pay tax from outside cash; elect 0% withholding on the conversion itself.
Five-year model example
| Year | Age | Other taxable income | Conversion | Approx. federal tax on conv. |
|---|---|---|---|---|
| 1 | 62 | $30,000 | $170,000 | $33,000 |
| 2 | 63 | $30,000 | $170,000 | $33,000 |
| 3 | 64 | $30,000 | $170,000 | $33,000 |
| 4 | 65 | $60,000 | $140,000 | $28,000 |
| 5 | 66 | $60,000 | $140,000 | $28,000 |
Total converted: $790,000. Total federal tax: ~$155,000 (effective rate ~19.6%) — versus a likely 24%+ marginal rate at age 75 with stacked RMDs and Social Security.
Coordinating with Social Security and RMDs
Delaying Social Security to 70 is often the single most powerful pairing with a conversion ladder. Each year of delay (a) frees bracket space for conversion in that year, and (b) raises the inflation-adjusted lifetime income floor by roughly 8% per year of delay between Full Retirement Age and 70.
Once the first RMD lands, every dollar of RMD displaces a dollar of conversion headroom. The ladder must front-load.
Timing mistakes to avoid
- Waiting for "a better year" — every unused year is permanent lost capacity.
- Converting in March, then realizing a Q4 capital gain that crosses the IRMAA tier.
- Claiming Social Security at 62 and then converting — provisional-income math punishes the combination.
- Stopping the ladder at age 70 — useful headroom often remains until the first RMD year.
Stephen Arnold
Founder & CEO of Wealth Protection Advisory. Pension and retirement planner with 20+ years advising small business owners. Creator of the Designer DB Plus® strategy and author of Designer DB Plus® Game-Changing Tax Reduction & Retirement Strategy.