The “Roth window” is the stretch of years when Roth conversions are most flexible and tax efficient. For many investors, it opens once full-time work ends and taxable income drops. It often runs from retirement through the calendar year before required minimum distributions begin. For most people, that’s before age 73.
During this window, you can “fill” your preferred tax bracket by converting just enough pre-tax IRA or 401(k) dollars to a Roth IRA each year. The idea is simple. Move money into a tax-free account at a known tax cost while you still control your income. Done thoughtfully, this reduces future RMDs, diversifies your tax buckets, and can lower lifetime taxes.
What changes at 73
Age 73 triggers required minimum distributions, or RMDs, from traditional IRAs and most employer plans. Your first RMD is due by April 1 of the year after you turn 73. Every year after that, the deadline is December 31. If you delay the first RMD until April 1, you will take two RMDs in that second year.
RMDs shrink the Roth window for three reasons.
First, RMDs are taxable income. They consume space in your tax bracket, which leaves less room for a tax-efficient Roth conversion.
Second, RMD dollars cannot be converted. The law bars you from counting any part of an RMD as a rollover or a Roth conversion. You must take the RMD first, then convert separate dollars. Trying to convert the RMD creates an excess Roth contribution that must be corrected.
Third, higher income can raise Medicare costs through IRMAA, the income-related surcharges for Parts B and D.
IRMAA uses a two-year lookback. A conversion you do this year can raise your Medicare premiums two years later.
You can appeal if a qualifying life event reduced your income, using Social Security Form SSA-44.
Why the window narrows, not slams shut
There is no age limit for conversions. What changes is sequencing and the side effects on taxes and premiums. You must satisfy the year’s IRA RMD before converting any additional dollars to a Roth. That ordering rule applies across all your IRAs.
Roth IRAs have no lifetime RMDs for the original owner. Employer Roth accounts now get the same treatment. Beginning in 2024, designated Roth accounts in 401(k) and 403(b) plans are no longer subject to lifetime RMDs.
When it comes to Roth IRAs, it’s important to understand the two distinct five-year rules that govern withdrawals and conversions.
Tax-free earnings rule : To withdraw earnings from your Roth IRA tax-free, two main criteria must be met: the five-year rule and the age requirement.
You must wait five years from your first contribution for your earnings to be withdrawn tax-free. While you do not have to be 59½ years old for the earnings to be tax-free if you meet the five-year requirement, reaching this age is important for avoiding a 10% early withdrawal penalty, particularly on converted amounts.
If you’re over 59½, you won’t face this penalty regardless of when you convert, but the five-year rule still applies to ensure that the withdrawn earnings are tax-free.
Early withdrawal penalty on conversions : The second five-year rule focuses on conversions from a traditional IRA to a Roth IRA. Each conversion has its own five-year clock, which aims to determine when you can withdraw the converted amounts without incurring a 10% early withdrawal penalty. This rule applies specifically if you are under the age of 59½ at the time of withdrawal. If you withdraw earlier than five years from a specific conversion, that amount could be subject to penalties even if you’ve reached the age of 59½.
Understanding these rules is crucial for effective tax planning and maximizing the benefits of your Roth IRA.
What to do once RMDs start
Consider qualified charitable distributions. If you are at least 70½, you can send up to a statutory limit (up to $108,000 in 2025) each year directly from your IRA to a qualified charity. A QCD counts toward your RMD once you are subject to RMDs, and it keeps that amount out of your income. Confirm the current limit each year.
Consider a QLAC. A QLAC is a deferred income annuity that can be funded with assets from a traditional IRA or an eligible employer-sponsored qualified plan like a 401(k), 403(b), or governmental 457(b). You can select an income to begin at any age up to 85. The amount invested in the QLAC is removed from your RMD calculations. QLAC limits in 2025 are up to $210,000.
After you take your RMD, you can still do partial conversions. The case for doing so hinges on your future tax outlook, estate goals, and IRMAA thresholds
Before age 73, you have more control over their income and can strategically plan conversions to manage taxes effectively. You can time income related to capital gains, business earnings, charitable contributions, and deductions.
Once RMDs begin, the government mandates a minimum distribution from your retirement accounts, which reduces your control over income timing. This minimum distribution often increases with age, potentially leading to higher taxable income and causing you to exceed thresholds for certain tax benefits, like IRMAA or increasing the taxable portion of Social Security.
Backdoor Roth after age 73
If your income is too high for a direct Roth IRA contribution, you can still fund a Roth through a backdoor Roth strategy after age 73. The process is straightforward. You make a non-deductible contribution to a traditional IRA, then convert that contribution to a Roth IRA. There’s no age limit for making a traditional IRA contribution as long as you (or your spouse, for a spousal IRA) have taxable compensation.
For 2025, the IRA contribution limit is $7,000, plus a $1,000 catch-up if you’re 50 or older.
Be aware of the pro-rata rule. If you have other pre-tax IRA money, the taxable portion of the conversion is based on the ratio of after-tax basis to your total IRA balance (traditional, SEP, and SIMPLE IRAs combined). If most of your IRA assets are pre-tax, most of the conversion will be taxable.
If you’re over 70½ and want to use Qualified Charitable Distributions (QCDs), be careful about the type of IRA contributions you make. Deductible contributions to a traditional IRA after 70½ will reduce the portion of future QCDs that can be tax-free.
With a backdoor Roth, you’re making non-deductible IRA contributions and then converting them to a Roth. Because those contributions aren’t deductible, they won’t reduce your ability to make fully tax-free QCDs later.
For someone over 73 who is taking required minimum distributions, this means you can still use the backdoor Roth strategy without hurting your QCD tax benefits. Just make sure the contributions are non-deductible.
Younger investors take note
The current RMD age is 73. For younger investors, it rises to 75 starting in 2033 under current law. That will expand their Roth window.
Final thoughts
Roth conversions are about control. The years before RMDs offer the most control because you choose how much income to realize and when. Once RMDs start, conversions remain possible, but sequencing, IRMAA, and bracket management become more challenging.
