Waiting on your Roth conversion costs real money because a traditional IRA keeps growing tax-deferred, so each delayed year enlarges the balance the IRS later taxes and narrows the low-tax window before RMDs begin.
Key Takeaways
- Converting during the low-income window before age 73 (75 if born in 1960 or later) is usually the cheapest time, because RMDs then stack forced income on top.
- In 2026 the 22% bracket begins at $50,400 for single filers and $100,800 for joint filers.
- IRMAA Medicare surcharges apply above $109,000 (single) or $218,000 (joint) MAGI in 2026, on a two-year lookback, with a Part B base premium of $202.90.
- The 3.8% net investment income tax thresholds are $200,000 (single) and $250,000 (joint).
- A Roth conversion is irreversible and must be completed by December 31.
- You cannot convert the RMD itself; the full required minimum distribution must be taken first before any amount above it can be converted.
Roth Conversion Timing By The Numbers (2026)
Figures reflect 2026 IRS and Medicare amounts and vary by household.
Understanding why waiting on your Roth conversion costs you real money comes down to timing: the low-income years between retiring and your first required minimum distribution are the cheapest window you will ever get to convert. Delay compresses that window, stacks future RMDs on top of your income, and can push more of your savings into higher tax brackets permanently.
Table of Contents
Stop the Clock on Your Conversion Cost
Our team has built more than 2,400 multi-year conversion plans, and the sample plan in this article reflects patterns we see across thousands of households. Find out what waiting is actually costing your specific situation — with no product pitch and no obligation.
Waiting on a Roth conversion is costly because a traditional IRA keeps growing tax-deferred, so every delayed year enlarges the balance the IRS eventually taxes as ordinary income. Each year of delay compresses the low-tax retirement-to-RMD window and pushes more of that balance toward higher future brackets. Converting during the low-income window (before age 73, or 75 if born in 1960 or later) is usually cheapest.
Why do people wait on a Roth conversion (and why do those reasons feel reasonable)?
People wait on a Roth conversion for reasons that feel prudent: market uncertainty, complex accounts spread across custodians, an over-scheduled CPA, a spouse still weighing in, or a wish for a clearer moment. None of these are irrational. Each one, though, quietly converts into a measurable lifetime tax cost, because a conversion is taxable ordinary income that gets more expensive as the IRA balance grows.
The most common reasons households give for pushing the decision to next year:
- Markets feel uncertain. Volatility makes any large financial move feel premature.
- Account complexity. Traditional IRAs at several custodians, plus 401(k)s and inherited IRAs, can create paralysis about which account to touch first.
- CPA bandwidth. Many households want to coordinate with a CPA but feel it is intrusive right after filing season.
- Spouse alignment. One spouse is on board while the other is still warming up to the idea.
- The “wait until things settle” instinct. A general sense that a clearer moment is coming.
These reasons are common and grounded in real life. The catch is that a Roth conversion is irreversible and must be completed by December 31, so a year of hesitation is a year of the low-tax window closing that you cannot get back.
What does waiting one year vs. five years actually cost?
Waiting on a Roth conversion is costly in a consistent direction, even though the exact figure varies with IRA balance, age, income, and tax law. Each delayed year narrows the low-tax conversion window and enlarges the future taxable balance, so more of that balance tends to be taxed later, often at a higher bracket than the one available today.
| Decision | Illustrative window impact | Illustrative effect on future tax |
|---|---|---|
| Convert now, full low-tax window | Widest low-tax window | Smallest share of the balance taxed later |
| Wait one year | Narrower window | More of the balance taxed later |
| Wait five years | Materially narrower window | Substantially more taxed later |
The cost is not created by a worse plan. It comes from a narrower window and a larger tax-deferred balance. Waiting does not erase that tax; it moves the money from what a household, a surviving spouse, and eventually heirs would have kept into ordinary-income tax paid later, often at a higher rate.
Deciding the size and pace of each conversion is its own question. Our educational overview of how much to convert to Roth walks through filling lower brackets without spilling into higher ones.
Why does compounding now work against you?
Compounding works against you once wealth sits in a traditional IRA, because every dollar of tax-deferred growth is a dollar the IRS can later tax as ordinary income. The same force that built the balance now enlarges the eventual tax bill. A statement showing $2 million contains a share that was never fully yours to spend, and delay grows that share year by year.
The mirror image is the Roth. More years inside a Roth means more tax-free compounding, so a delayed conversion shrinks the growth runway that makes the strategy pay off. Starting earlier is also why the Roth conversion break-even point tends to arrive sooner: the tax-free compounding has more time to overtake the tax paid up front.
Paying tax now at a known bracket, rather than on a larger balance at an unknown future bracket, is the core trade. In 2026 the 22% bracket begins at $50,400 for single filers and $100,800 for joint filers, so the gap years below those thresholds sit in the 10% and 12% brackets. Converting to fill that lower-bracket space costs far less than distributing forced income later in the 24% or 32% brackets.
Why is the value in execution, not the plan in a folder?
The value of a Roth conversion lives in execution, not in a plan sitting in a folder. A plan is the math: brackets, sequencing, and projections. The dollar outcome comes from acting on it, coordinating a CPA, an investment advisor, an estate attorney, and a spouse, and timing conversions to real conditions. A full planning year gives that coordination room to work; a compressed December rarely does.
A late start does not necessarily produce a worse plan. What it compresses is the execution window: the number of months available to identify which holdings to convert first, to coordinate estimated tax payments, and to convert when market and tax positioning align rather than in the final weeks of the year.
When is the cheapest time to convert, and why does the RMD window close it?
The cheapest time to convert is usually the gap years between retiring and your first required minimum distribution, when earned income has stopped but RMDs and often Social Security have not yet started. Taxable income can dip into the 10% or 12% bracket, so converting fills lower brackets cheaply. Once RMDs begin at age 73 (75 if born in 1960 or later), that forced income stacks on top and the window narrows.
RMDs do not replace your other income; they pile on it. A retiree with pension and Social Security income who adds a six-figure RMD can be pushed into a higher bracket for the rest of life, and the increase is permanent because RMDs recur every year. Sizing that future obligation early is the point of reviewing required minimum distributions in 2026 before the first distribution year arrives.
The added income also has side effects beyond the bracket. Higher modified adjusted gross income can trigger IRMAA, the Medicare surcharge that applies above $109,000 for single filers and $218,000 for joint filers in 2026 (Part B base premium $202.90), on a two-year lookback. A conversion is taxable ordinary income and is not itself subject to the net investment income tax, though the extra income can raise MAGI toward the 3.8% NIIT thresholds ($200,000 single, $250,000 joint) and toward IRMAA.
Can you convert in an RMD year?
You can do a Roth conversion in a year you owe an RMD, but you cannot convert the RMD itself. IRS rules require taking the full required minimum distribution first, and that distribution is taxable and must stay out of the Roth. Only amounts above the RMD may be converted, and they land on income that is already high, which is why converting before RMDs begin is usually cheaper.
How does waiting hit the surviving spouse (widow’s trap)?
Waiting hits the surviving spouse through the widow’s penalty: after the first spouse dies, the survivor usually files single, where the same income meets narrower brackets and lower IRMAA thresholds than the joint figures. A large traditional IRA that was manageable for a couple can push a widow or widower into a higher bracket and Medicare surcharges. Converting earlier can shrink that inherited tax exposure.
The gap is concrete. In 2026 the standard deduction is $32,200 for joint filers but $16,100 for a single filer, the 22% bracket starts at $50,400 single versus $100,800 joint, and IRMAA begins at $109,000 single versus $218,000 joint. The survivor keeps much of the household income while losing the wider joint thresholds, so a balance drawn down through conversions during the couple’s years often costs less over two lifetimes.
How to get your plan moving this year
Investors looking to get a Roth conversion moving this year often quantify the future RMD first, then coordinate the people and the timing while the calendar still cooperates. A conversion is irreversible and must be completed by the Roth conversion deadline of December 31, so sequencing it earlier can preserve more of the low-tax window. The steps below show how intent often becomes an executed multi-year plan.
- Quantifying the future RMD against current income, Social Security, and pension projections, so the size of the problem is visible.
- Bringing the CPA in early, between filing seasons, to set estimated payments and withholding.
- Aligning both spouses on the strategy, not just informing one of them, so the plan does not stall.
- Looping in the estate attorney if converting changes how accounts pass to heirs.
- Building the multi-year sequence with an advisor before the year compresses.
Households that want a coordinated, multi-year approach can review Q3’s educational Roth conversion planning overview to see how the pieces fit together.
Common mistakes that raise the cost of waiting
Common mistakes that raise the cost of waiting share a theme: they shrink the low-tax window or delay execution. Treating a conversion as a December transaction, postponing the CPA conversation, leaving a spouse out of the decision, confusing a plan with a result, and waiting for markets to feel certain all push conversions into higher-income years, where the same dollars carry more tax.
- Treating the conversion as a December event. A real plan needs a full year of runway; the last six weeks are not enough.
- Postponing the CPA conversation. The accessible time to coordinate is between filings, not during them.
- Leaving a spouse out of the decision. Plans stall most often when one spouse is not fully in the room.
- Confusing “I have a plan” with “I have a result.” A plan in a folder does not reduce taxes; execution does.
- Waiting for markets to feel certain. They rarely do; the right moment is when the household’s situation supports the move.
Frequently asked questions
When is the cheapest time to do a Roth conversion?
The cheapest time to do a Roth conversion is often the gap years between retiring and your first required minimum distribution, when earned income has stopped and RMDs have not begun. Taxable income frequently drops into the 10% or 12% bracket, so converting fills low brackets cheaply. Within the year, starting early keeps the full window open; the conversion must be completed by December 31.
Is it too late to do a Roth conversion after retirement?
It is not too late to do a Roth conversion after retirement. Retirement often opens the cheapest conversion window, because earned income has stopped while RMDs have not yet begun at age 73 (75 if born in 1960 or later). Many retirees convert during these lower-income years. Conversions stay available at any age, though income sources and IRMAA thresholds shape how much to convert.
How much does waiting one year on a Roth conversion cost?
Waiting is costly in a consistent direction, though the exact figure varies with IRA balance, age, income, and tax law. Each delayed year narrows the low-tax window and enlarges the tax-deferred balance that the IRS later taxes as ordinary income, so more of that balance tends to be taxed later, often at a higher bracket than the one available now.
Can you do a Roth conversion in the year you take an RMD?
Yes, you can do a Roth conversion in a year you take an RMD, but IRS rules require you to take the full required minimum distribution first, and the RMD itself cannot be converted. Only amounts above the RMD may move to a Roth, and they stack on top of income that is already high. This is why converting before RMDs begin is usually less expensive.
What is the Roth conversion window before RMDs start?
The Roth conversion window before RMDs start is the stretch between leaving earned income and the year required minimum distributions begin, at age 73, or 75 for those born in 1960 or later whose first age-75 RMD year is 2035. During these gap years, taxable income is often lowest, so converting can fill the 10%, 12%, or 22% brackets before forced income arrives.
Does converting before RMDs actually lower my taxes?
Converting before RMDs can lower lifetime taxes by moving money out of a traditional IRA while your bracket is low, which shrinks the balance that later drives required minimum distributions. Smaller future RMDs mean less forced ordinary income, a lower chance of IRMAA Medicare surcharges (above $109,000 single or $218,000 joint MAGI in 2026), and more assets compounding tax-free in the Roth.
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Q3 Advisors is a registered investment adviser focused on retirement tax planning. This page is educational and is not advice; consult a qualified professional.
