The Roth Strategy That Could Save You $100,000 in Future Taxes

You earned $620,000 last year. You're a surgeon, an executive, a business owner. You've heard that Roth IRAs are for people earning under $150,000. You make more than four times that. So you wrote off the Roth entirely.

Here's what no one told you: there is no income limit on a Roth conversion.

The Backdoor Roth IRA and the Mega Backdoor Roth are two strategies that work specifically for high earners — and most CPAs never mention them. Combined, they can put hundreds of thousands of dollars into a tax-free account over your career. With tax rates set to rise in 2026 under the TCJA sunset, the window to do this cheaply is closing.

Why Roth Conversions Matter More Than Ever (Before 2026)

Here's the math the CPA who files your taxes once a year isn't running.

The Tax Cuts and Jobs Act (TCJA) lowered individual tax rates through 2025. In 2026, unless Congress acts, rates snap back to pre-2018 levels. The top marginal rate goes from 37% to 39.6%. The 24% bracket becomes 28%. The 32% bracket becomes 36%.

What does that mean for you? Every dollar you convert to Roth today is taxed at today's rates — which are the lowest they're likely to be for the rest of your career.

A doctor earning $500,000 who converts $50,000 from a traditional IRA to a Roth pays approximately $18,500 in tax on that conversion at today's top rate. Wait until 2026 and the same conversion costs roughly $19,800 — a difference of $1,300 on that single conversion. Do this annually for a decade and you're looking at $13,000+ in unnecessary tax, plus the compounding loss on that money.

But the real power isn't in the rate arbitrage. It's in what happens next: that $50,000 grows tax-free for the rest of your life.

Strategy 1: The Backdoor Roth IRA

The Backdoor Roth IRA is a two-step process that lets high earners contribute to a Roth IRA regardless of income. Here's how it works:

1. Contribute to a Traditional IRA — You can contribute $7,500 in 2025 ($8,000 if you're 50+). There's no income limit on contributing to a Traditional IRA — there's only a limit on deducting the contribution if you have a retirement plan at work.
2. Convert to Roth — Immediately convert that Traditional IRA to a Roth IRA. You pay ordinary income tax on any pre-tax dollars converted. If you do it right after contributing (before the money grows), there's virtually no tax due.

The real-world scenario:

Meet Dr. Torres. She's a cardiothoracic surgeon earning $680,000 a year. Like most doctors, she assumed Roth IRAs weren't available to her. Her CPA never brought it up.

She starts doing a Backdoor Roth IRA at age 40. Every year, she contributes $7,500 to a Traditional IRA and converts it to Roth. By age 65, assuming 7% annual growth, that one decision puts $516,000 into a tax-free account — and she never pays a dollar of tax on the withdrawals.

That's half a million dollars in tax-free retirement income from a strategy her CPA never mentioned.

The catch: If you have an existing Traditional IRA with pre-tax money, the pro-rata rule applies — you can't convert just the non-deductible portion. But if your current IRA is empty (or rolled into your 401k), this strategy works cleanly.

Strategy 2: The Mega Backdoor Roth — The $70,000 Move

If the Backdoor Roth IRA is impressive, the Mega Backdoor Roth is transformative.

Some 401(k) plans allow something called after-tax contributions — separate from your pre-tax deferrals and Roth contributions. In 2025, the total limit for employee plus employer contributions to a defined contribution plan is $70,000 ($77,500 if 50+). The Mega Backdoor Roth lets you contribute after-tax money up to that limit, then convert it to Roth.

The real-world scenario:

Meet Marcus, an executive at a publicly traded healthcare company. His total comp is $720,000. His 401(k) plan allows after-tax contributions and in-plan Roth conversions. Here's his setup:

• Pre-tax 401(k): $23,500 (max)
• Employer match: $12,000
• After-tax contribution: $34,500 (pushing to the $70,000 limit)
• Total into Roth via conversion: $34,500/year

Marcus does this every year for 15 years. At 7% growth, that's $902,000 in a Roth account — every dollar of growth completely tax-free.

Compare that to investing the same money in a taxable brokerage account, where every dividend, every capital gain, and every withdrawal is taxed. The difference over a retirement lifetime is easily $100,000–$200,000+.

Why your CPA didn't tell you this: Most CPAs don't administer 401(k) plans. They don't read plan documents. They don't know whether your plan allows after-tax contributions. The only way to find out is to ask your plan administrator — or work with a tax strategist who specializes in high-income planning.

When NOT to Convert — And What to Do Instead

Roth conversions aren't always the right move. Here's when to pause:

You're in your peak earning years. If you're earning $800K and expect to drop to $200K in retirement, converting at 37% today to save 24% later doesn't make sense. The goal is to convert when your marginal rate now is equal to or lower than your expected rate in retirement.

You need the cash to pay the tax. Never convert if you'd have to sell investments at a loss to pay the conversion tax. The tax on a conversion must be paid from non-retirement funds.

You have a large Traditional IRA. Thanks to the pro-rata rule, converting a $500,000 IRA to Roth in one year would trigger a massive tax bill. Partial conversions over multiple years are more strategic.

For many high earners, the optimal approach combines strategies: max out your Defined Benefit Plan or Cash Balance Plan to get a massive deduction today, use some of the tax savings to fund a Backdoor Roth IRA, and convert gradually over low-income years or early retirement.

Your Next Move

You don't need to earn $200K to use a Roth. You need to earn $300K+ to need one — because you're the one who will benefit most from tax-free growth and tax-free withdrawals in retirement.

The window to convert at today's rates closes at the end of 2025. Every year you wait is a year of tax-free compounding you'll never get back.

Book a free 30-minute strategy session. This isn't a sales pitch — it's a no-obligation conversation where you'll learn exactly what you've been leaving on the table. Call (619) 280-2700 or email info@RoadmapTax.com.

---

FAQ

What is a Backdoor Roth IRA?

A Backdoor Roth IRA is a two-step strategy where you contribute to a Traditional IRA (no income limit) and then convert those funds to a Roth IRA. It allows high earners to access Roth accounts despite income limits on direct contributions.

How much can I contribute to a Backdoor Roth IRA in 2025?

The annual limit is $7,500 for those under 50 and $8,000 for those 50 and older. This is the total IRA contribution limit, not an additional limit.

What is the Mega Backdoor Roth 401(k) strategy?

The Mega Backdoor Roth lets you contribute after-tax dollars to your 401(k) beyond the standard $23,500 limit, up to $70,000 total (including employer contributions), and convert those after-tax funds to Roth. Not all plans allow this.

Is there a tax penalty for doing a Roth conversion?

You pay ordinary income tax on any pre-tax dollars you convert. There's no penalty. The key is converting at a tax rate that's lower than or equal to what you'd pay in retirement.

Do Roth conversions make sense if tax rates go up in 2026?

Yes — that's exactly the point. Converting now at today's lower TCJA rates means you pay less tax upfront. Every dollar converted before 2026 saves you the difference between today's rate and the higher post-2025 rate.

Should I convert my entire Traditional IRA to Roth at once?

Not necessarily. Converting a large IRA in one year can push you into a higher bracket. Most high earners benefit from partial conversions spread over multiple years, converting only up to the top of their current bracket.