One of the biggest retirement planning mistakes I see is assuming taxes will automatically go down once work stops.
Sometimes they do. But if you’ve built up a large traditional IRA or 401(k), retirement can create a temporary tax window that’s far more valuable than most people realize.
If I retire at 65 with a large pre-tax balance, but RMDs don’t start until 75, that 10-year gap can be a planning gift. Those may be the years when I have the most control over my tax bracket.
Here’s the basic idea:
A Roth conversion means moving money from a traditional IRA to a Roth IRA and paying tax on that amount now. That’s the painful part. The benefit is that once the money is in the Roth, future growth can be tax-free, withdrawals can be tax-free if rules are met, and there are no RMDs during the owner’s lifetime.
That matters because the real risk isn’t just taxes today. It’s letting a large traditional IRA keep compounding until the IRS starts forcing income out of it.
In the example I reviewed, a retired couple starts with $1.5 million in a traditional IRA at 65. If they do nothing and the account grows at 6%, it can swell to roughly $2.7 million by age 75. That can produce a first RMD of around $109,000.
Add Social Security on top of that, and now we’re talking about a very different tax picture than most retirees expected.
By contrast, if that same couple uses the pre-RMD years to convert aggressively—but intentionally—they may be able to keep filling lower brackets on purpose rather than letting future RMDs dictate the outcome. In this example, the strategy reduced the IRA entering age 75 to only a few hundred thousand dollars, with a first RMD closer to $11,000.
That’s a dramatic shift.
And yes, the modeled lifetime tax savings were enormous—close to $400,000. But I want to be very clear: I would never present that as a typical outcome. That kind of result usually requires a very specific combination of factors:
- a large traditional IRA
- a real low-income window before RMDs
- enough years to do meaningful conversions
- outside funds available to pay the conversion tax
- no large pension already filling up the brackets
Still, the lesson is sound.
Roth conversions are not about avoiding taxes.
They’re about paying taxes more intelligently.
What I like most about this strategy is that it puts the retiree back in control. Instead of waiting for a bloated IRA to create large forced withdrawals later, I can decide when to recognize income and how much bracket space I want to use each year.
That’s fiduciary planning. It’s not flashy. It’s not hype. It’s just good tax management.
A few cautions, though.
Roth conversions are not automatically a win. If I expect to be in a meaningfully lower bracket later, the math may not work. If I’m using IRA money itself to pay the conversion tax, the benefit shrinks. If conversions push me into Medicare premium surcharges or create other ripple effects, that has to be modeled too.
And this is where I part ways with a lot of generic advice online: the strategy is only as good as the tax projection behind it.
I want to see the full picture:
- current bracket
- future RMDs
- Social Security taxation
- Medicare IRMAA exposure
- widow’s penalty risk
- state taxes
- legacy goals
Without that, a Roth conversion is just a guess dressed up as a strategy.
If you’re in your 60s, recently retired, and sitting on a large tax-deferred balance, this is absolutely worth a serious look. The years before RMDs begin can be some of the best planning years you’ll ever get.
In many cases, the choice is simple:
Pay some tax now by design, or pay a lot more later by default.