The short answer
A Roth conversion strategy is a plan for moving money from a traditional IRA or similar pre-tax account into a Roth IRA over one or more years. The converted amount is generally taxed as income in the year of the conversion. A strategy is the plan for how much to convert, and when, weighed against the tax cost.
What a Roth conversion is
Money in a traditional IRA has usually not been taxed yet. When you convert some of it to a Roth IRA, the IRS generally treats the untaxed part as income for that year. The IRS describes the mechanics, and the fact that a conversion is reported on Form 8606, in its IRA FAQs.
In exchange for paying that tax now, qualified distributions from a Roth IRA are generally tax-free if the IRS requirements are met, and the owner is not required to take withdrawals while alive (see the IRS pages on Roth IRAs and required minimum distributions). The trade-off is real: you pay tax earlier than you otherwise would, and a conversion may not come out ahead for every household.
Taxes are not the place for fireworks. Think slow training arc, not Spirit Bomb: small, steady, and planned.
When a conversion may make sense
These are situations where a conversion is often worth modeling. None of them is a recommendation, and each comes with a limit.
- A low-income gap year. Some people have a stretch after they stop working and before Social Security or required withdrawals begin. Taxable income may be lower in those years, so added income from a conversion may be taxed differently than it would be later. The limit: the conversion still raises that year’s income, and the effects below still apply.
- Before required minimum distributions start. Under the IRS’s current guidance, RMDs from traditional IRAs generally begin at age 73, and Roth IRAs have no RMDs during the owner’s lifetime. Converting earlier may reduce the balance that future RMDs are calculated on. The limit: you pay tax on the converted amount now, and tax law can change.
- Before Social Security begins. Social Security benefits may become partly taxable when your other income is higher. Converting before benefits start may keep that interaction out of the picture for those years. The limit: the conversion itself can raise income in the year it happens.
- Planning for heirs. Some households care about what they leave behind. Inherited Roth IRAs still have distribution timing rules, generally ten years for many beneficiaries, so the benefit depends on the heir’s situation.
When a conversion may not make sense
- There is no cash outside the IRA to pay the tax, so the tax would come out of the converted money.
- Income this year is already high, and the converted amount would be added on top of it.
- The conversion would push income past a Medicare premium threshold or reduce Marketplace premium help, and the added cost outweighs the benefit.
- You may need the money soon. A Roth IRA has its own timing rules, including separate five-year periods that the IRS explains in Publication 590-B.
- You expect to be in a lower tax bracket later and have no estate-planning reason to convert.
Whether a conversion fits depends on your income, your tax picture, and your plans. A projection built on your actual tax return can show it, and a general guide cannot.
Bracket filling and multi-year conversions, explained
Federal income tax is progressive: each slice of taxable income is taxed at its own rate, and the IRS publishes the rate schedules and brackets each year at irs.gov. A conversion adds to your taxable income, so a very large one in a single year can push part of your income into a higher bracket.
“Bracket filling” is the idea of converting only enough in a given year to stay within a bracket you have chosen, then repeating the process in later years. A multi-year approach seeks to spread the added income out rather than take it all at once.
It is a planning technique and not a promise. The trade-offs include more years of tracking and paperwork, brackets that may change, and other thresholds (such as Medicare premiums) that can matter as much as the bracket itself.
Side effects to check before converting
The converted amount is income, so it can ripple into other parts of a retiree’s finances.
- Medicare premiums (IRMAA). Medicare Part B and Part D premiums can be higher for people with higher income. The Social Security Administration generally uses your tax return from two years earlier to decide, so income in a conversion year can show up in premiums two years later. See the SSA’s handbook section on income-related premiums. This matters most for people who are 63 or older, because income at that age can affect their first Medicare premiums at 65.
- Social Security taxation. Whether your benefits are taxable depends on your combined income, and up to 85% of benefits can be included in taxable income. A conversion raises that income. See IRS Publication 915.
- Marketplace health coverage. If you buy coverage through the Health Insurance Marketplace before Medicare, premium help is based on your expected household income for the year. A conversion may reduce it. See HealthCare.gov.
- State income tax. State treatment varies. New York residents can confirm how New York handles a conversion with the NY Department of Taxation and Finance.
- Paying the tax from outside funds. Taking the tax out of the converted amount reduces what lands in the Roth IRA, and the IRS notes a 10% additional tax can apply to early distributions taken before age 59½ unless an exception applies. Paying from savings outside the IRA is a common approach, if you have them.
- The pro rata rule. If you hold after-tax money in any traditional, SEP, or SIMPLE IRA, a conversion is treated as coming proportionally from all of those IRAs, so you cannot pick only the after-tax dollars. See our guide to the pro rata rule for Roth conversions.
- No undo button. The IRS says conversions made in 2018 or later cannot be recharacterized back to a traditional IRA (see the Form 8606 instructions). Once it is done, it is done.
A hypothetical example
Hypothetical, for illustration only. The numbers below are made up and rounded. They are not a recommendation, they do not describe any client, and they assume no investment returns.
Picture a married couple in their mid-60s who have recently retired and are living on savings, with Social Security not yet started. They have a traditional IRA and cash in a savings account outside it.
| Other taxable income | Hypothetical conversion | Income reported | |
|---|---|---|---|
| One large conversion, Year 1 | $40,000 | $90,000 | $130,000 |
| Year 1 of three | $40,000 | $30,000 | $70,000 |
| Year 2 of three | $40,000 | $30,000 | $70,000 |
| Year 3 of three | $40,000 | $30,000 | $70,000 |
Both approaches convert the same $90,000 in total. Splitting it into three years keeps each year’s reported income lower than the one-year version. That may reduce the chance of landing in a higher bracket or crossing a Medicare premium threshold, and it may not. The table does not show tax owed, because that depends on filing status and the current IRS rate schedules. It also does not show the cost of spreading things out: three years of planning, the chance that rules change, and two additional years in which the account stays in a traditional IRA.
Year-end timing: the December 31 deadline
A conversion counts for the tax year in which the money moves out of the traditional IRA. To count for 2026, it generally has to be completed by December 31, 2026, and the later filing deadline does not extend that. The IRS explains the tax-year rules in Publication 590-A. As of October 29, 2026, that leaves a short window.
Custodians can take days to process a transfer, and some have their own cutoff dates ahead of year-end. If you are considering a conversion, it helps to look at your full-year income estimate first, including any RMD, which must be taken before anything else (the IRS says an RMD cannot be rolled over, so it cannot be converted).
Roth conversion strategy calculator: what to look for
Free calculators can be a useful first pass. A good one asks for more than a balance. Look for tools that let you enter:
- Your filing status and other taxable income for the year
- Whether Social Security has started, and how much
- Medicare premium thresholds (IRMAA) and the two-year lookback
- Where the tax will be paid from, inside or outside the IRA
- State income tax
A calculator only reflects the numbers and assumptions typed into it, and it is not a substitute for a review of your full return. A review of your full tax return is where an IRS Enrolled Agent can help.
How a CFP® and an IRS Enrolled Agent look at it together
A conversion sits where retirement planning and tax planning meet. The retirement side asks how much income you need and when Social Security and RMDs begin. The tax side asks what a conversion would do to your return, and what it would do to your premiums.
Our team includes Certified Financial Planners® and IRS Enrolled Agents, so those questions can be reviewed together. N Financial Plans is a fee-only, fiduciary firm, so we accept no commissions and sell no products. You can see how we are paid on our fees page.
If you already have an advisor and want another view before year-end, a complimentary financial second opinion is a low-pressure place to start.
Sources and as-of dates
Rules and thresholds change. Everything below was reviewed on October 29, 2026. Confirm current figures at the source before you act.
- IRS: Retirement plans FAQs regarding IRAs (conversion methods, Form 8606)
- IRS: Roth IRAs
- IRS: Retirement topics, required minimum distributions (age 73, no lifetime RMDs from Roth IRAs)
- IRS: RMD FAQs (RMDs cannot be rolled over; ten-year rule for beneficiaries)
- IRS: Instructions for Form 8606 (no recharacterization of 2018 and later conversions)
- IRS: Publication 590-A and Publication 590-B
- IRS: Publication 915 (taxation of Social Security benefits)
- SSA: Handbook section 2504 (income-related Medicare premiums and the two-year lookback)
- HealthCare.gov: Estimate your expected income
This guide is educational. It is not individualized tax, legal, or investment advice, and it is not a recommendation that you convert. Any benefit of a conversion, such as tax-free qualified withdrawals or smaller RMDs, comes with limits such as an upfront tax cost and effects on brackets and Medicare premiums, and results vary by household.
