Do You Need a Financial Advisor for a Roth Conversion? When DIY Works and When to Hire One

A Roth conversion looks deceptively simple on paper. You move money from a traditional IRA or 401(k) into a Roth, pay ordinary income tax on the amount converted, and from that point forward the money grows and comes out tax free. No future required minimum distributions, no tax on the gains, and the account passes to heirs tax free as well.

The mechanics take ten minutes at your custodian. The math behind the decision is anything but simple. A conversion is essentially a bet that your tax rate today is lower than it will be later, and that bet has to account for federal brackets, state taxes, Medicare premiums, Social Security taxation, ACA subsidies, capital gains stacking, and the size of the RMDs you'd otherwise face starting at age 73 or 75.

Here's how to tell when you can run the numbers yourself and when paying a flat fee to an advice-only financial planner will pay for itself many times over.

Why Roth Conversions Are a High-Stakes Decision

Michael Kitces has written extensively about the fact that the "true" marginal tax rate of a Roth conversion is rarely the same as the bracket you see on the IRS table. A $50,000 conversion at the 22% federal bracket might actually cost you closer to 35% or 40% once you factor in the additional taxation of Social Security benefits, a jump into a higher IRMAA tier on Medicare, lost ACA premium subsidies, or the loss of the 0% capital gains rate.

That gap between the "headline" rate and the true rate is where most DIY conversions go wrong. The mechanics are easy, but the optimization is where the dollars are won or lost.

A recent Kiplinger analysis documented cases where retirees triggered effective conversion tax rates above 50% by stacking ordinary income, capital gains, and Social Security all into the same year. None of those costs show up on the conversion confirmation page at Fidelity or Vanguard.

The Five Hidden Costs Most DIY Investors Miss

When you compute whether a conversion makes sense, the conversion amount touches at least five other parts of the tax code:

1. IRMAA on Medicare premiums. Medicare uses a two-year lookback, so a 2026 conversion drives your 2028 Part B and Part D premiums. Cross an IRMAA threshold by even one dollar and the premium increase applies to the whole year. Couples can pay several thousand dollars more per year per spouse with one cliff crossed.

2. Social Security taxation. Up to 85% of your Social Security benefits become taxable once provisional income crosses thresholds set decades ago and never indexed to inflation. A conversion that pushes you past those thresholds means each dollar of Roth conversion costs you ordinary income tax plus extra tax on a portion of your Social Security check.

3. Capital gains stacking. Long-term capital gains and qualified dividends sit on top of ordinary income. A Roth conversion stacks ordinary income underneath, which can push gains that would have been taxed at 0% up into the 15% bracket, or gains at 15% into 20%, plus a possible 3.8% net investment income tax.

4. ACA premium subsidies. If you retire before 65 and use a marketplace plan, a Roth conversion can vaporize your premium tax credit. For a couple with moderate income, that subsidy is often worth $10,000 to $20,000 per year, far more than the headline tax bill on the conversion itself.

5. State taxes. A few states tax Roth conversions at high rates, and a few don't tax retirement income at all. If you'll be moving in retirement, the question of when to convert (before or after the move) can be a six-figure decision on its own.

Schwab's tax planning team and Vanguard's advisor tax center both maintain calculators that try to capture these interactions, but the tools assume you already know which inputs matter and which years to model.

When You Can Probably DIY a Roth Conversion

You can usually handle a conversion yourself if all of the following are true:

• You are at least five years away from Medicare (so IRMAA isn't in play yet).
• You are not yet drawing Social Security.
• You have no ACA marketplace plan with a premium tax credit on the line.
• The conversion does not push you into a new federal bracket.
• You have no large capital gains or qualified dividends in the same year.
• You are converting a small amount (typically under $25,000) relative to your income.

These are the "low complexity" conversions where the headline tax bracket is roughly equal to the true marginal rate. A taxpayer in their 40s or early 50s doing a backdoor Roth, or partial conversions in the 12% bracket while in early retirement before Social Security, can usually run the numbers in a spreadsheet or with a tool like Boldin or Pralana and get a reasonable answer.

When to Hire a Financial Advisor for a Roth Conversion

The cost-benefit flips the moment any of the following enter the picture:

• You're between 60 and 72, where the conversion window is narrow and IRMAA, Social Security timing, and RMDs all interact.
• You have a large traditional IRA or 401(k) (roughly $750,000 or more) where future RMDs will likely push you into a higher bracket regardless of what you do today.
• You are on an ACA marketplace plan and would lose subsidies by converting.
• You have a pension, an inherited IRA on a 10-year drawdown clock, or other "income you can't control" that complicates the bracket math.
• You expect to move to a different state in retirement.
• You want to plan a multi-year conversion ladder rather than one big conversion.
• You're trying to coordinate conversions with charitable giving (qualified charitable distributions, donor-advised funds, appreciated stock).

In these cases, the value the right planner adds is not in pressing the conversion button. It is in choosing the right amount, the right year, and the right sequence to convert, while staying under the IRMAA tier you want, preserving the ACA subsidy you need, and avoiding stacking capital gains on top of ordinary income.

A 2024 Vanguard analysis put the value of tax-efficient withdrawal and conversion strategies at up to 1.1% per year of additional after-tax return. For a household with $1.5 million in retirement assets, that is roughly $16,500 per year, every year, for the rest of your life. A single Roth conversion analysis can be worth more than that on its own.

Why Advice-Only Is the Right Fit for Roth Conversion Work

Roth conversion planning is almost a textbook case for the advice-only model. The work is intense for a few months while the analysis is built and the conversion is executed, then minimal in later years until the next decision. You don't need someone managing your portfolio. You need someone to model the interaction between brackets, IRMAA, Social Security, and your specific account balances, then tell you exactly how much to convert and when.

A traditional 1% AUM advisor often won't accept a project this narrow, and if they do, the fee structure penalizes you. Paying 1% of $1.5 million ($15,000 per year) every year to revisit a decision you make once is not aligned with the work being done. For a deeper dive on the math, see our breakdown of whether a 1% AUM fee is worth it.

Advice-only planners, by contrast, charge for the project. Based on data from 97 advice-only planners on the Advice-Only Network (March 2026):

• One-time plan (n=76): p25 $2,000, median $3,000, p75 $4,500
• Hourly (n=75): p25 $250/hr, median $300/hr, p75 $360/hr
• Monthly ongoing (n=48): p25 $199/mo, median $250/mo, p75 $399/mo

A focused Roth conversion analysis typically lands in the one-time plan range, or 6 to 12 hours of work at hourly rates. Some clients prefer the monthly ongoing structure so the advisor can revisit the conversion plan each year as tax law, account balances, and income change.

What to Ask a Planner Before You Hire One

Roth conversion work is technical enough that you should screen carefully. A few questions worth asking:

• Are you a CFP® professional and a fiduciary at all times, in writing?
• Do you use specialized retirement and tax projection software (Income Lab, Holistiplan, RightCapital, Pralana) for conversion analysis, or just generic planning tools?
• Can you walk me through how you model IRMAA, Social Security taxation, and ACA subsidies in a conversion plan?
• How many Roth conversion analyses have you done in the last twelve months?
• Will the deliverable include a multi-year conversion schedule I can actually execute, or a single recommendation for this year only?

For a longer list, see our guide to the questions to ask any financial advisor before you hire.

The Bottom Line

A Roth conversion is one of the highest-leverage financial decisions most people will ever make, and the difference between a well-planned conversion and an unplanned one is often tens of thousands of dollars over a retirement. For simple, low-income situations, DIY is fine. For everyone in or near retirement with meaningful traditional IRA balances, paying a flat fee to an advice-only CFP® professional is one of the clearest cases where the advice pays for itself.

The conversion form itself takes ten minutes. The decision about how much, when, and over how many years deserves more than ten minutes of thought.