How Much Should You Roth Convert Every Year?
The goal is not to convert the most. The goal is to pay the least tax over your lifetime.
One of the most common retirement-planning questions is:
“How much should I convert to a Roth IRA each year?”
People often expect a simple answer—a fixed dollar amount, a percentage of the IRA, or a rule such as “convert up to the top of the 24% tax bracket.”
But Roth conversions should not be treated like annual contributions. There is no universal amount that works every year.
The appropriate conversion could be:
$0 during a high-income year
$50,000 during an ordinary retirement year
$200,000 or more during an unusually favorable planning window
A Roth conversion is ultimately a tax trade. You voluntarily recognize taxable income today in exchange for potentially tax-free qualified withdrawals and fewer taxable retirement distributions later.
The IRS permits you to convert all or part of a traditional IRA. The taxable portion is generally included in income during the year of conversion, and conversions completed after 2017 generally cannot be reversed through recharacterization.
That makes the amount—and the timing—extremely important.
Do Not Start With This Year’s Tax Bracket
Many Roth-conversion strategies begin by asking:
“How much room do I have left in my current tax bracket?”
That is a useful calculation, but it is not the entire analysis.
The better question is:
“How much income should I intentionally recognize this year based on the taxes I am likely to pay over the rest of my life?”
That requires comparing the cost of converting today with the potential future cost of leaving the money in a traditional retirement account.
Future taxable income may include:
Required minimum distributions
Social Security benefits
Pension income
Portfolio income
Business or rental income
Future retirement-account withdrawals
Distributions inherited by children or other beneficiaries
Traditional retirement accounts can eventually create taxable required distributions, while Roth IRAs are not subject to required minimum distributions during the original owner’s lifetime.
A retiree who appears to be in a modest tax bracket today may therefore face considerably more taxable income later.
Your Tax Bracket Is Not Your True Conversion Cost
Suppose you are in the 24% federal tax bracket.
It may be tempting to assume that every additional dollar converted costs 24 cents in federal tax. But the actual cost can be higher because a conversion increases adjusted gross income and may affect other parts of your financial plan.
A conversion could potentially:
Increase Medicare Part B and Part D premiums
Reduce Marketplace health-insurance subsidies
Cause more Social Security income to become taxable
Expose additional investment income to other taxes
Affect deductions, credits, or capital-gains taxation
Generate state income tax
Increase estimated-tax or withholding requirements
For Medicare recipients, this is particularly important. Medicare generally uses modified adjusted gross income from two years earlier when determining whether income-related premium surcharges apply.
For retirees purchasing health insurance through the Marketplace before age 65, the premium tax credit is also income-sensitive. A larger conversion can reduce the credit or potentially eliminate it.
This is why Roth conversions should be evaluated using an effective marginal tax rate, not merely the tax bracket printed on a tax table.
A Practical Way to Calculate the Conversion
A useful starting framework is:
Potential Roth conversion = target income ceiling minus projected income before the conversion minus a margin of safety
But the “target income ceiling” must be selected carefully.
It could be:
The top of a chosen federal tax bracket
An income level below a Medicare threshold
An income level that preserves health-insurance subsidies
A state-tax threshold
The point at which the lifetime benefit of converting begins to decline
The potential conversion should therefore be the lowest amount supported by:
Your available federal and state tax-bracket capacity
Any income-based thresholds you want to preserve
The cash available to pay the conversion tax
A multiyear retirement-income and tax projection
You should also leave a buffer for unexpected dividends, capital gains, bonuses, business income, or other year-end adjustments.
A Simplified Example
Assume a retired couple projects $120,000 of taxable income before completing a Roth conversion.
After evaluating their future required distributions, Medicare exposure, capital gains, state taxes, and available cash, they select $200,000 as their initial planning ceiling.
That creates preliminary conversion capacity of:
$200,000 − $120,000 = $80,000
Rather than converting the entire $80,000 immediately, they might initially convert $65,000 or $70,000 and reserve the remaining capacity until their year-end income becomes clearer.
In November or December, the tax projection can be updated. If their income is lower than expected, they can complete an additional conversion.
This approach reduces the risk of accidentally crossing an expensive threshold—and is especially important because completed Roth conversions generally cannot be undone.
The Most Valuable Roth-Conversion Window
For many households, the best opportunity occurs after retirement but before required distributions and other income sources begin.
During this period, employment income may have ended, while Social Security, pensions, and required distributions may not yet have fully started.
This temporary gap can provide several years of unusually favorable conversion capacity.
Other potentially attractive opportunities include:
A temporary drop in income.
A sabbatical, layoff, business slowdown, or unusually large deduction may create a lower-tax year.
A significant market decline.
When investments fall in value, the same number of shares can be converted at a lower taxable value. Any subsequent recovery then occurs inside the Roth account.
Before moving to a higher-tax state.
Converting while living in a state with lower or no income tax may reduce the total conversion cost.
Before the death of a spouse.
A married couple may want to reduce large traditional retirement balances before the surviving spouse begins filing under a less favorable single-taxpayer structure.
Before passing retirement accounts to high-income heirs.
Children may inherit traditional retirement accounts during their own peak earning years. The parents’ tax rate may be lower than the beneficiaries’ future tax rate.
When a Large Conversion May Be a Mistake
Roth conversions are not automatically beneficial.
Converting aggressively may be unattractive when:
You are already experiencing an unusually high-income year
You expect to withdraw the money later at a meaningfully lower tax rate
You would have to use a large portion of the IRA itself to pay the taxes
The conversion would create substantial Medicare or health-insurance costs
You expect to leave much of the traditional IRA to charity
You may need the converted money in the near future
The tax payment would weaken your emergency reserves or investment plan
“Tax-free” does not automatically mean “better.”
Paying a large tax bill today to avoid a smaller tax bill later is not good planning.
Roth Conversion Planning Should Be Updated Every Year
The optimal amount is not static.
Income changes. Markets change. Tax laws change. Account values change. Family circumstances change.
A disciplined annual process might include:
Early in the year: Estimate income, deductions, capital gains, and available conversion capacity.
During the year: Monitor portfolio distributions, business income, charitable giving, and major financial events.
In the fall: Update the tax projection using better year-to-date information.
Before year-end: Complete the final conversion while allowing sufficient time for the custodian to process it.
The IRS notes that taxable conversion income may require additional withholding or estimated-tax payments, so the conversion and the tax-payment strategy should be coordinated.
The Bottom Line
There is no single amount that everyone should Roth convert each year.
The appropriate answer may be:
Nothing during a business-sale year
A modest amount while receiving Marketplace subsidies
A larger amount during the years between retirement and required distributions
An opportunistic conversion after a market decline
The objective is not to produce the same conversion every year.
The objective is to determine how much taxable income should be recognized today to improve the family’s lifetime after-tax outcome, reduce future tax concentration, and create greater flexibility in retirement.
At Analog Capital Partners, we believe Roth conversions should be coordinated with investment management, retirement income, Medicare, charitable planning, estate planning, and the client’s broader financial strategy.
Do not ask only, “How much can I convert?”
Ask:
“What multiyear conversion strategy gives me and my family the best after-tax result?”
Roth conversions are irrevocable and can have significant tax consequences. Individual strategies should be coordinated with a qualified financial advisor and tax professional
