Roth IRA Conversions: When They Make Sense (and When They Don't)
Roth conversions are one of those strategies that get pitched as a universal good idea. They're not. Done right, a Roth conversion can save you, or your heirs, a significant amount in lifetime taxes. Done wrong, you're writing the IRS a check today for a benefit you'll never fully realize.
Here's how to think through it clearly.
What a Roth Conversion Actually Is
A Roth conversion is the process of moving money from a traditional IRA (or other pre-tax retirement account) into a Roth IRA. The amount you convert gets added to your taxable income for the year. You pay ordinary income tax on it now, and in exchange, that money grows tax-free and comes out tax-free in retirement.
It’s a simple concept but the complexity is in the math.
When Roth Conversions Make Sense
1. You're in a Lower Tax Bracket Now Than You Expect to Be Later
This is the core logic. If you're in a 22% bracket today and expect to be in a 32% bracket in retirement, because of Social Security, RMDs, a pension, or rental income, converting now locks in the lower rate. You're essentially prepaying taxes at a discount.
This happens a lot in the years between retirement and age 73 (when required minimum distributions kick in). If you retire at 62, stop drawing a W-2, and haven't started Social Security yet, you may have a window of low taxable income. That window is prime Roth conversion territory.
2. You Have a Long Time Horizon
The tax-free compounding needs time to work. If converted funds sit in a Roth for 20–30 years, the math gets compelling fast. The shorter the runway, the harder it is to break even on the upfront tax hit.
3. You Want to Leave Tax-Free Assets to Heirs
Traditional IRAs passed to non-spouse beneficiaries must be fully distributed within 10 years under current law, and those distributions are taxable. A Roth IRA passed to heirs still has the 10-year rule, but the distributions are tax-free. For high-net-worth estates, this is a significant planning lever.
4. You Can Pay the Tax Bill from Outside the IRA
This one matters more than most people realize. If you convert $50,000 and have to pull the tax money from the IRA itself, you're reducing the amount that gets to compound tax-free. The best conversions are funded with outside money, a taxable brokerage account, savings, whatever. That way, the full converted amount stays in the Roth working for you.
5. Your State Has No Income Tax (or You're Moving to One)
If you live in Florida, Texas, Nevada, or another no-income-tax state, you're only paying federal on the conversion. If you're planning to move from a high-tax state to a no-tax state in retirement, you probably want to wait and convert after the move. Timing this right can save a meaningful amount.
When Roth Conversions Don't Make Sense
1. You're Already in a High Tax Bracket
This is probably the most common mistake. If you're in the 35% or 37% bracket today, converting a large chunk of your traditional IRA means paying top-dollar taxes right now, hoping that future rates will be even higher. That's a bet with low odds. Even if rates go up modestly, you've already paid a steep price. The math rarely works at these income levels unless you have a very specific estate planning objective.
For most people currently earning at the top brackets, the better play is to let pre-tax money stay pre-tax and focus on other tax strategies.
2. You Need the Money Soon
If you're going to need the converted funds in the next few years, you've taken the tax hit without getting the compounding benefit. Roth accounts need time. Converting in your late 60s or early 70s just to have "tax-free money" can backfire if you end up spending it down quickly anyway.
There's also the 5-year rule to be aware of: each Roth conversion has its own 5-year clock for penalty-free access to the converted principal (separate from the rule on earnings). If you're under 59½ and might need the money, this matters.
3. The Conversion Would Push You Into a Higher Bracket or Trigger Clawbacks
This is where the planning gets granular. Converting $80,000 might push your income over a threshold that:
Increases your Medicare Part B and D premiums (IRMAA surcharges)
Makes more of your Social Security taxable
Phases out certain deductions or credits
Triggers the net investment income tax
The marginal cost of the conversion in these scenarios can be much higher than the stated bracket rate. A CPA should model this before you pull the trigger, not after.
4. You're in a State With High Income Tax and Not Planning to Leave
If your state taxes ordinary income at 9–13%, converting a large IRA position is a combined federal + state hit that may never make sense unless you have a very long time horizon or significant estate planning goals. Run the numbers with both rates included.
5. You Don't Have Outside Funds to Pay the Tax
If the only way to cover the tax bill is to take it from the IRA itself, the conversion math gets much harder to justify. You're shrinking the base that needs to compound. In some cases, a smaller strategic conversion (versus a large one) is the better move.
The Bottom Line
Roth conversions aren't a blanket good idea, and they aren't a blanket bad idea. They're a tool, and like any tool, the value depends entirely on how and when you use it.
The best candidates are generally people in temporarily low-income years (between retirement and RMDs, or between jobs) who have time for the account to grow, can pay the tax from outside funds, and have a clear sense of what their future tax picture looks like.
If you don't have that clarity, that's exactly what tax planning is for.
This content is for informational purposes only and does not constitute tax or investment advice. Every situation is different — consult your CPA or financial advisor before making any conversion decisions.
