Sam's Economics

Should you convert your IRA to a Roth, and how much each year?

Compare leaving your traditional IRA alone with converting enough each year to fill a tax bracket. See lifetime taxes, Medicare surcharges, the survivor years, and what your family keeps after tax.

Your numbers

Defaults are Greg and Elena from the video. Change anything.

Today

Traditional IRA balance

$100k$5M

Savings outside the IRA (pays conversion tax)

$0$2M

Your age now (both spouses)

5574

Required withdrawals start at

Social Security

Couple's benefits per year

$0$120k

Survivor's benefit per year

$0$80k

Benefits start at

6270

The plan

Convert each year up to the top of

Conversions run from now until required withdrawals start.

First spouse dies at

6595

Compare through age

8095

Return after inflation

0%8%

Heirs' tax rate on what's left in the IRA

0%40%

AFTER-TAX WEALTH AT 90

—

Leave the IRA alone

—

Convert each year

—

Taxes + surcharges, incl. heirs

—

Federal tax + Medicare surcharge, year by year

Age	Convert	Tax (convert)	Required withdrawal (wait)	Tax (wait)

Converted in total

—

Left in the IRA at the end (wait)

—

Compare every bracket

After-tax wealth at the end for each conversion ceiling, your other inputs held.

Plan	After-tax wealth	vs leaving it alone	Taxes incl. heirs

Verdict

The three traps

1Medicare looks back two years. Conversions from 63 on can raise Medicare premiums if income crosses $218,000 for a couple ($109,000 single) in 2026.
2Marketplace health insurance before 65. Conversion income can shrink premium subsidies.
3Paying the tax from the IRA. Less grows tax-free, and before 59½ it can add a 10% penalty. Conversions can't be undone.

Get the conversion worksheet, the 2026 bracket table and the questions to ask your tax professional.

Download the PDF guide

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Illustrative estimate only, not tax or financial advice. Each year: required withdrawal (balance ÷ IRS Uniform Lifetime factor) from the RMD age; in the convert plan, a conversion sized so taxable income reaches the top of the chosen bracket, until the RMD age. Taxable Social Security uses the federal provisional-income formula. Tax uses 2026 brackets (married filing jointly until the first death, single after), the standard deduction ($32,200 / $16,100) plus $1,650 per spouse ($2,050 single) from 65. Medicare surcharges use 2026 IRMAA tiers (Part B + Part D) for each person 65+. Taxes and surcharges are paid from savings; required withdrawals are added to savings. All accounts grow at the return you set, in today's dollars, with no tax on savings growth. After-tax wealth = Roth + savings + IRA × (1 − heirs' rate). Sources: IRS Rev. Proc. 2025-32 (2026 brackets), CMS 2026 IRMAA tiers, SECURE 2.0 (RMD age 75 for those born 1960 or later).