Picture a 66-year-old who just retired with most of her savings in a traditional 401(k). Her paycheck has stopped, Social Security has not started, and required minimum distributions are still years away. For the first time in four decades, her taxable income has fallen off a cliff.
Those in-between years are one of the most valuable tax planning windows a retiree ever gets. Most households let them expire unused.
Why These Years Are Different
Through your working life, salary fills the lower tax brackets before any planning begins. In early retirement the opposite happens. With wages gone and required distributions not yet triggered, many retirees land in the lowest bracket they have seen since their twenties.
Left alone, the low-income stretch simply runs out. The window closes on a schedule:
| Milestone | What changes |
|---|---|
| Retirement day | Wages stop and taxable income drops. The window opens. |
| Age 63 | Income starts counting toward Medicare’s IRMAA surcharges, which look back two years from age 65 enrollment. |
| Social Security begins | Benefit income layers in, and conversion income can make more of it taxable. |
| RMD age (currently 73 under the SECURE 2.0 rules) | Required withdrawals stack on top of everything else. The window closes. |
The Roth Conversion Opportunity
A Roth conversion moves money from a traditional IRA or 401(k) into a Roth IRA. You pay ordinary income tax on the converted amount now. In exchange, the money grows tax-free, comes out tax-free, and is never subject to lifetime required distributions for the original owner.
Conversions are taxed in the year they happen, which is exactly why the quiet window matters. Converting during low-income years means paying tax at the bottom of the bracket ladder instead of the top.
The approach many planners use is bracket filling, repeated annually:
- Estimate the year’s income once it has mostly taken shape, typically in the second half of the year.
- Pick the bracket you are willing to fill and find the dollar distance between your income and the top of it.
- Convert up to that line, not past it.
- Re-check the ripple effects before finalizing, then repeat next year.
A hypothetical couple with $800,000 in traditional accounts might convert a measured slice each year across a seven-year window, moving a meaningful share of the balance at controlled rates instead of letting required distributions set the rate for them later.
The Ripple Effects to Check First
Conversion income does not exist in a vacuum. Before converting a dollar, look at what else it touches:
- Social Security taxation. Conversion income can increase how much of your benefit is taxable in that year.
- Health insurance credits. Retirees buying marketplace coverage before Medicare can lose premium credits as income rises.
- Medicare surcharges. IRMAA looks back two years, so a large conversion at 64 can raise premiums at 66.
- How the tax gets paid. Paying conversion tax from a taxable account, rather than from the converted dollars, lets the full amount keep working inside the Roth.
Who Benefits and Who Should Pass
The window tends to matter most for households with large traditional balances, sizable projected required distributions, or heirs in high-earning years. Under current law, most non-spouse beneficiaries must empty inherited retirement accounts within ten years, and inherited Roth dollars come out tax-free while inherited traditional dollars are taxed as ordinary income.
Conversions are not automatic wins. Passing can be the better call for retirees who expect lower future brackets, plan large charitable gifts directly from their IRAs, or need every dollar for near-term spending.
Worth Remembering
- The window is finite. Every year between retirement and required distributions that passes unexamined is a bracket you cannot get back.
- Bracket filling beats lump converting. Measured annual slices control the rate.
- Ripples count. Medicare, Social Security, and health credits all react to conversion income.
- December 31 is the deadline for that tax year’s conversion, so this is second-half-of-the-year work.
A conversation with a financial professional and your tax preparer can map how many window years you have and what each one is worth.
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Kingsbury Financial Advisors is a full-service comprehensive financial planning and wealth management firm located in Tampa, Florida. Alongside our strategic partnership with the leading comprehensive financial planning firm Caitlin John Private Wealth management, we have all of the necessary resources to support our clients in conquering their financial goals.
Kingsbury Financial Advisors was founded by Sefton Kingsbury Barnes II. Sefton has worked with over 300 households building personalized financial plans with a focus on helping his clients realize their dreams.
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