The window runs from your last paycheck until Required Minimum Distributions begin, at 73, or 75 if you were born in 1960 or later. Salary has stopped and RMDs have not started, so taxable income falls to its lowest point in decades. Converting pre-tax savings during those years means paying tax in low brackets before RMDs fill them.
Most of retirement planning is about the money. This part is about the calendar.
For roughly a decade after the last paycheck, a household’s taxable income falls to a level it has not seen since early in a career and will not see again. Salary has stopped. Required Minimum Distributions have not started, because the SECURE 2.0 Act set that age at 73, or 75 for anyone born in 1960 or later. Social Security is often deferred, since benefits grow about 8% a year between full retirement age and 70.
The result is a stretch of years where the household decides how much income to recognize. That is unusual. During working years the employer decides, and once RMDs begin the IRS decides.
The window is shorter than it sounds
Ten years is the headline number. The real one depends on your retirement date and your birth year.
| Retire in 2026 at | Years before RMDs begin |
|---|---|
| 62 | 13 |
| 65 | 10 |
| 67 | 6 |
| 70 | 3 |
Retire at 62 or 65 in 2026 and your RMDs start at 75; retire at 67 or 70 and they start at 73. A couple retiring at 67 has six filing years to work with, and the first of them is a partial year still carrying salary. Five usable years is a common real answer, not ten.
What the room is worth
The room is the gap between your actual taxable income and the top of a bracket you are willing to fill. Converting pre-tax savings to a Roth account uses that gap at today’s rate instead of leaving the balance to grow into an RMD taxed at whatever rate applies later.
The size of the opportunity scales with two things: how much sits in pre-tax accounts, and how many years remain. A household with $2 million in a 401(k) and eight years of window has a materially different problem from one with $600,000 and four years. Any figure quoted without both of those numbers is decoration.
The same logic runs in reverse. A large pre-tax balance left alone does not stay still. It compounds, and the RMD divisor shrinks as you age, so the required withdrawal climbs in both dollars and percentage terms. The bill is not avoided by ignoring it. It is deferred into a year you do not control.
Three things that close the window early
Claiming Social Security. Benefits become taxable income once provisional income crosses $32,000 for a couple, and up to 85% is taxable above $44,000. Those thresholds have never been indexed to inflation. Claiming early fills the bracket room you were planning to convert into.
Starting a pension or a deferred compensation payout. Non-qualified deferred compensation distributes on a schedule elected years earlier, and Section 409A restricts changing it. A payout landing in year two of a planned conversion sequence does not just reduce the room. It can push the conversion itself into a higher bracket.
Medicare. IRMAA surcharges are set from your income two years earlier, so a conversion at 63 shows up in the premium at 65. The surcharge is a cliff rather than a slope: one dollar over a threshold moves the whole year to the next tier. Conversions sized without checking the thresholds can cost more in premiums than they saved in tax.
Why the window gets missed
Three reasons, in the order I see them.
The first is that nobody names it. A household that has been told for thirty years to defer tax does not hear “recognize income on purpose” as advice. It sounds like a mistake.
The second is that the cost arrives before the benefit. A conversion means writing a check this April for a result that shows up over twenty years. That trade is easy to defend on a spreadsheet and hard to feel.
The third is capability. The American College of Financial Services surveyed 478 advisors in March 2026 and found that nearly 6 in 10 who list retirement income planning among their top services demonstrate only basic or intermediate proficiency in it. Most advisors were trained to grow a balance. Spending one down is a different job.
What to do with this
The window is a planning object, not a tactic. It has a start date, an end date, an annual capacity, and a set of events that shrink it. Mapping it means knowing your pre-tax balance, your retirement date, your Social Security claiming plan, any deferred compensation schedule, and the IRMAA thresholds for the years in question, and then deciding how much room to use each year.
That mapping is the centerpiece of every Retirement Income Roadmap we build. It is also the piece most often missing from the plans people bring us.
Talk it through
Mapping your own window takes your balances, your retirement date, and your claiming plan. Schedule a conversation with Robert Boeck, to see what yours is worth.
The figures in this article are illustrative and describe mechanisms rather than predictions. Tax rules change, and the right answer depends on your own balances, income, and timeline.
Common questions
- When does the retirement tax planning window open and close?
- It opens when earned income stops and closes when Required Minimum Distributions begin under the SECURE 2.0 Act: at 73, or 75 if you were born in 1960 or later. Retiring at 62 in 2026 gives roughly 13 years. Retiring at 67 gives six. The window is shorter than most people assume, and it never reopens.
- Why are these years lower-income than the years around them?
- Salary has ended, RMDs have not started, and Social Security is often deferred to earn delayed retirement credits. For a year or more the household may have almost no taxable income beyond what it chooses to recognize, which is what makes the bracket room usable.
- What closes the window besides reaching RMD age?
- Claiming Social Security early, starting a pension, or taking a large deferred compensation distribution all raise taxable income and narrow the room available. Each of those is a timing decision, which is why they belong in the same plan as the conversion schedule.
- Is a Roth conversion always the right use of the window?
- No. Conversions cost tax today for a benefit that arrives later, and the case weakens if your retirement bracket will be lower than your current one, if you expect to give the money to charity, or if paying the tax would require selling assets at a bad time.
If the decisions on this page are ahead of you, the two of you can work through them with Robert Boeck before any of them becomes permanent.
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