There is a stretch of years in many people’s lives that almost nobody plans for on purpose.
It often begins when the paycheck stops and is especially valuable before Social Security begins and required minimum distributions take effect. For some people, it is two years. For others, it is eight or ten. During those years, your taxable income may be the lowest it has been since your twenties — and potentially the lowest it will ever be again.
I call this period the Quiet Window: the years when earned income has fallen, but Social Security and required minimum distributions have not yet fully filled the income gap.
That window can be one of the most valuable planning opportunities in your financial life.
Most people spend it doing nothing because doing nothing feels like the safe choice. Then Social Security begins, required distributions eventually arrive, Medicare premiums enter the picture, and the tax flexibility available during those quiet years may be gone.
The opportunity is not simply to convert money to a Roth. The real opportunity is to determine how much to convert, in which years, and at what tax cost.
First, a word about what this strategy is actually called
You will hear the term “backdoor Roth” used loosely to describe almost any move of money into a Roth account. It is worth separating the two because they solve different problems.
A backdoor Roth is a contribution strategy. It is generally used by people whose income is too high to contribute directly to a Roth Individual Retirement Account. They make a nondeductible contribution to a traditional Individual Retirement Account and then convert that amount to a Roth Individual Retirement Account.
A Roth conversion is what this article is about.
You take money that already sits in a traditional Individual Retirement Account or eligible workplace retirement plan, pay the income tax on the taxable amount now, and move it into a Roth account where it can potentially grow and later be distributed tax-free if the applicable requirements are met.
Unlike Roth Individual Retirement Account contributions, Roth conversions are not subject to an annual income eligibility limit or a statutory dollar cap, although workplace retirement plan rules may affect when and how plan assets can be converted.
You might convert $10,000, $50,000, $100,000, or more.
The important question isn’t simply how much you can convert.
It is how much you should convert.
One old argument for converting has changed. Three stronger ones remain.
For years, one argument for Roth conversions came with a deadline: individual tax provisions were scheduled to change after 2025.
That scheduled expiration is no longer on the calendar. The One Big Beautiful Bill Act, signed into law in July 2025, made key provisions of the current individual income tax structure permanent under current law.
That does not eliminate the case for Roth conversions. It changes the conversation.
One: Your personal tax rate can go up even if tax laws don’t.
Required minimum distributions begin at age 73 for many retirees and at age 75 for people born in 1960 or later.
When required minimum distributions begin, the government determines a minimum amount that generally must come out of your tax-deferred retirement accounts each year.
A traditional retirement account that has compounded for thirty or forty years can create significantly more taxable income in retirement than you anticipated needing.
That income can affect more than your tax bill. It can influence the taxation of Social Security benefits, Medicare premiums, and other parts of your financial plan.
Converting strategically during lower-income years can reduce the balance that will eventually produce required minimum distributions.
Two: Eventually, one spouse may file as a single taxpayer.
This is one of the most overlooked issues in retirement tax planning.
In many married couples, one spouse will eventually outlive the other. The surviving spouse may still have much of the household’s taxable income but eventually moves from married filing jointly to single tax brackets, a smaller standard deduction, and significantly lower Medicare income thresholds.
That can create a substantial tax difference later in retirement.
Roth conversions completed while both spouses are living and filing jointly can be one way to reduce the surviving spouse’s future exposure to taxable retirement distributions.
Three: The money you leave behind may be on a ten-year clock.
Under current law, many non-spouse beneficiaries — including adult children — who inherit a retirement account must fully distribute the account within ten years.
For an adult child inheriting a large traditional Individual Retirement Account, those distributions may arrive during some of that child’s highest-earning years.
Traditional Individual Retirement Account distributions generally create taxable income for the beneficiary.
A qualified Roth Individual Retirement Account inherited by that same child can generally be distributed income-tax-free, although inherited Roth accounts remain subject to beneficiary distribution rules.
That means Roth conversion planning isn’t only a retirement-income decision.
It can also be an estate and generational-wealth decision.
Then Social Security starts, and the math changes
Social Security benefits are not automatically taxable, and they are not automatically tax-free.
How much of your benefit is included in taxable income depends on a separate calculation commonly referred to as provisional income — generally your other income, plus tax-exempt interest, plus half of your Social Security benefits.
Cross certain thresholds and up to 50 percent of your benefits may become taxable. Cross the higher threshold and up to 85 percent may become taxable.
Here is where Roth conversion planning becomes particularly interesting.
Once you are collecting Social Security, an additional dollar of retirement account withdrawal or conversion income doesn’t necessarily affect only that dollar. Additional income can also cause more of your Social Security benefit to become taxable.
As a result, someone who appears to be sitting comfortably in the 12 percent or 22 percent federal tax bracket may discover that the true marginal cost of additional income is higher than the tax bracket alone suggests.
Converting before you claim Social Security avoids that particular interaction entirely because there is no Social Security benefit yet to pull into taxable income.
That doesn’t automatically mean you should convert as much as possible before claiming Social Security.
It means those years deserve to be modeled deliberately rather than allowed to pass by default.
And then there is Medicare — the part that surprises people two years later
This is where good intentions can get expensive, so it deserves special attention.
Medicare Part B and Part D premiums are not the same for everyone.
Above certain income levels, beneficiaries pay an additional amount called the Income-Related Monthly Adjustment Amount (IRMAA).
Three features of IRMAA matter enormously when considering a Roth conversion.
It generally looks back two years.
Medicare generally determines your income-related premium using tax information from two years earlier.
For example, your 2026 Medicare premium generally uses income reported on your 2024 federal tax return.
That means income generated by a Roth conversion today may affect your Medicare premiums two years later.
It works more like a cliff than a tax bracket.
Ordinary income tax brackets apply the higher tax rate only to taxable income above the applicable threshold.
IRMAA works differently.
Cross an income threshold and you can move into a higher Medicare premium tier.
That means a relatively small amount of additional income — including Roth conversion income — can sometimes create a disproportionately large increase in Medicare premiums.
Roth conversion income counts.
The income calculation used for IRMAA generally includes adjusted gross income plus tax-exempt interest.
Wages, pensions, taxable capital gains, traditional retirement account withdrawals, and taxable Roth conversion amounts can all affect that calculation.
Qualified Roth Individual Retirement Account distributions generally do not.
And that is part of the long-term appeal of converting: you accept taxable income strategically today in exchange for potentially greater tax flexibility later.
The 2026 monthly Medicare Part B amounts
These figures are based on income reported on the 2024 tax return. Amounts are per person, so a married couple with both spouses enrolled can each be subject to the applicable premium.
2024 income — individual return 2024 income — married filing jointly Monthly surcharge Total Part B per month
$109,000 or less $218,000 or less $0.00 $202.90
$109,001 – $137,000 $218,001 – $274,000 $81.20 $284.10
$137,001 – $171,000 $274,001 – $342,000 $202.90 $405.80
$171,001 – $205,000 $342,001 – $410,000 $324.60 $527.50
$205,001 – $499,999 $410,001 – $749,999 $446.30 $649.20
$500,000 and above $750,000 and above $487.00 $689.90
A separate monthly surcharge ranging from $14.50 to $91.00 in 2026 applies to Medicare Part D prescription drug coverage at the same income tiers.
Now look at the first two lines.
A single Medicare beneficiary with income of $109,000 pays the standard $202.90 monthly Part B premium.
At $109,001, the Part B premium becomes $284.10.
That additional dollar of income can trigger $974.40 in additional annual Part B premiums.
Add the first-tier Part D adjustment of $14.50 per month and the additional annual Medicare cost becomes $1,148.40 for one beneficiary.
For a married couple where both spouses are Medicare beneficiaries and both are subject to the adjustment, the additional annual cost can be $2,296.80.
All because household income crossed a threshold.
That is why Roth conversion planning cannot be done by looking at tax brackets alone.
Why age 63 deserves special attention
Because Medicare generally uses income from two years earlier, income reported around age 63 may affect the Medicare premiums you initially pay when enrolling at 65.
This changes how Roth conversion planning should be sequenced.
“Convert aggressively before Medicare” may sound reasonable, but age 65 isn’t necessarily the only date that matters.
Age 63 can be an important planning marker.
After that point, Roth conversion decisions should generally be evaluated alongside Medicare income thresholds, with the potential Medicare cost included in the analysis.
But age 63 is not a hard deadline.
If your income later falls because of retirement, work reduction, the death of a spouse, divorce, marriage, or another qualifying life-changing event, you may be able to ask the Social Security Administration to use more recent income information when determining your IRMAA.
It is equally important to know what generally does not qualify. A Roth conversion, a home sale, or a one-time capital gain is not treated as a life-changing event. Income from those decisions generally has to wait out the two-year lookback period, which is exactly why the Medicare cost belongs in the analysis before the decision is made rather than after.
The point is not to fear crossing a Medicare threshold.
The point is to know the cost before you cross it.
A picture of how this goes wrong — and how it goes right
How it goes wrong.
A couple retires at 64. Wanting to be efficient, they convert a large traditional Individual Retirement Account balance in a single year and also sell an appreciated investment to fund the tax bill.
Their income for that year lands well into the Medicare surcharge tiers.
Two years later — while living on a modest and entirely different income — higher Medicare premium notices arrive.
The conversion may still have been worthwhile over their lifetimes.
But nobody calculated the Medicare cost before they made the decision.
How it goes right.
The same couple begins planning several years earlier.
They convert measured amounts each year, using multi-year tax projections to evaluate how much of a targeted tax bracket they want to fill while also watching Medicare thresholds, Social Security timing, capital gains, deductions, and other income.
When possible and appropriate, they pay the conversion tax from assets outside the retirement account so more of the converted amount remains invested inside the Roth.
By the time required minimum distributions begin, their traditional retirement balance is substantially smaller.
Their required minimum distributions may be lower.
Their taxable income may be lower.
They have greater control over where future retirement income comes from.
And the Roth assets eventually left to their daughter may provide her with substantially more tax flexibility.
Same couple. Same money. Different order of operations.
Before you convert a dollar, know these
* A Roth conversion generally cannot be undone. The ability to recharacterize a completed Roth conversion was eliminated beginning in 2018. If the market falls after you convert, the taxable amount isn’t recalculated simply because the account subsequently lost value.
* Consider paying the tax from outside money when practical. Using outside assets to pay the tax allows more of the converted amount to remain invested inside the Roth. If you are under age 59½, withholding money from the retirement account to pay taxes can also create additional tax or penalty considerations.
* Know the Roth five-year rules. Roth Individual Retirement Accounts have separate five-year rules governing qualified distributions of earnings and certain withdrawals involving converted amounts. The rules depend on age and individual circumstances, so completing a conversion does not necessarily mean every dollar is immediately available tax-free and penalty-free.
* State income tax matters too. The federal tax calculation is only part of the cost. Your state of residence today — and potentially where you expect to live later — can affect the economics of converting.
* Watch the temporary senior deduction. Current law provides an additional deduction of up to $6,000 per eligible person age 65 or older for tax years 2025 through 2028, subject to income limitations. The deduction begins phasing out at modified adjusted gross income above $75,000 for single filers and $150,000 for married couples filing jointly. A Roth conversion can therefore create a hidden marginal cost by simultaneously generating taxable income and reducing a deduction you otherwise might have received.
* If your income dropped because of a qualifying life-changing event, ask about an IRMAA appeal. Retirement or work stoppage, work reduction, marriage, divorce, and the death of a spouse are among the events that may qualify. Form SSA-44 allows you to request that the Social Security Administration use more recent income information when determining your Medicare income-related adjustment.
Who this is not for
A Roth conversion is not a universally correct answer, and anyone treating it as one has stopped doing the math.
Converting may be less attractive if you reasonably expect to be in a meaningfully lower tax bracket later, if paying the conversion tax would undermine your financial security, if additional income would cause you to lose valuable income-based health insurance subsidies before Medicare, or if you plan to leave substantial retirement assets directly to charity.
A qualified charity generally does not pay income tax when it receives traditional Individual Retirement Account assets. Converting those dollars and paying the tax yourself first may therefore provide little benefit.
There are also situations where deliberately crossing a tax bracket or a Medicare income threshold can make sense because the long-term benefit exceeds the short-term cost.
That’s why the objective should not simply be:
Pay the least tax this year.
The better question is:
How do I manage taxes over my lifetime?
The point
The years between your last paycheck and your first Social Security check are not a holding pattern.
They may be some of the most valuable tax-planning years of your retirement.
Decisions made during those years can show up in your tax return today, in your Medicare premium two years later, in your required minimum distributions years after that, and eventually in what your children inherit.
If you are within ten years of retirement — or recently retired — this is worth modeling before the decision is made by default.
At Advance Financial Lighthouse, we don’t look at a Roth conversion as an isolated transaction.
We build multi-year projections designed to answer the questions that matter:
How much should you convert?
In which years?
At what tax cost?
What happens to Social Security taxation, Medicare premiums, required minimum distributions, and the assets you ultimately leave behind?
The question isn’t simply whether a Roth conversion makes sense. It’s how much, in which years, and what else changes when you do it.
That’s the planning conversation worth having while your Quiet Window is still open.
Call (405) 843-2380 or schedule a conversation at https://oncehub.com/AFLscheduling
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Sources
* Centers for Medicare and Medicaid Services, “2026 Medicare Parts A and B Premiums and Deductibles,” fact sheet published November 14, 2025.
* Social Security Administration, Medicare premiums for higher-income beneficiaries, and Form SSA-44, “Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event.”
* Internal Revenue Service guidance regarding Roth conversions, required minimum distributions, Roth Individual Retirement Account distributions, inherited retirement accounts, and taxation of Social Security benefits.
* One Big Beautiful Bill Act, Public Law 119-21, enacted July 4, 2025.
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This material is for informational purposes only and is not intended as tax or legal advice. Neither Advance Financial Lighthouse nor its representatives may give tax or legal advice. Please consult your tax or legal professional regarding your individual situation.
Roth conversions are taxable events. The taxable amount converted is generally included in ordinary income in the year of conversion and may affect your tax bracket, deductions, taxation of Social Security benefits, Medicare premiums, health insurance subsidies, and other tax-related items. Tax and Medicare rules described here are current as of publication and are subject to change. Examples shown are hypothetical illustrations and are not representative of any specific person’s results.
Kathy Williams, RFC®, is founder and chief executive officer of Advance Financial Lighthouse, a fee-based fiduciary financial planning practice in Oklahoma City serving clients locally and nationwide.