Explainer
How does a Roth conversion affect Social Security?
By Secure Retirement PlannerUpdated
If you convert to a Roth, your Social Security check stays the same, but up to 85% of it can become taxable. The converted amount counts in your "provisional income", the formula the IRS uses to tax benefits.
Once yours passes $32,000 as a married couple, or $25,000 if you are single, part of your benefit becomes taxable. It starts at up to 50% and climbs to up to 85%. These lines are fixed in the tax code and never rise with inflation.
In some income ranges, each dollar you convert also pulls up to 85 cents of your Social Security into taxable income. People call this the tax torpedo. It can make your conversion in the 12% bracket cost about 22 cents per dollar.
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The short version
- Conversions don't lower your benefit, but they can make more of it taxable.
- The $25,000 / $32,000 and $34,000 / $44,000 lines have never been adjusted for inflation.
- In the torpedo zone, a dollar converted can add $1.50 to $1.85 of taxable income.
- Converting before you claim Social Security avoids this effect entirely.
- Qualified Roth withdrawals later don't count in provisional income.
How is provisional income figured?
Add up your other income: wages, pensions, IRA withdrawals, Roth conversions, interest and dividends. Then add any tax-exempt interest and half of your Social Security benefits. The IRS compares your total to the base amounts below.
A Roth conversion goes straight into your "other income", dollar for dollar.
| Provisional income, joint | Provisional income, single | Share of benefits that can be taxed |
|---|---|---|
| $32,000 or less | $25,000 or less | None |
| $32,000 to $44,000 | $25,000 to $34,000 | Up to 50% |
| Above $44,000 | Above $34,000 | Up to 85% |
What is the Social Security tax torpedo?
It's the income range where each extra dollar you add makes more of your Social Security taxable. In the 50% range, $1 of conversion adds $1.50 to your taxable income. In the 85% range, it adds $1.85.
So your 12% bracket can act like 18% or 22.2%. Your 22% bracket can act like 40.7%. The torpedo ends once 85% of your benefits are already taxed. After that, you pay only your bracket rate on each dollar again.
A quick check
If your tax return shows less than 85% of your Social Security as taxable, a conversion will likely make more of it taxable. You can find both numbers on line 6a and 6b of your Form 1040.
Does a Roth conversion reduce my Social Security benefits?
No. Your benefit itself does not shrink. Social Security has an earnings test that can hold back benefits if you claim before full retirement age and keep working. It counts only wages and self-employment income. Its rules say payments from your IRA, 401(k) or 403(b) don't count.
There is one indirect effect to watch. IRMAA is the extra Medicare premium you pay when your income is higher. If a conversion pushes you into an IRMAA tier, you pay a higher Part B premium two years later. It is usually taken out of your Social Security payment. So your deposit can shrink even though your benefit didn't. See Roth conversions and IRMAA.
Should I convert before I claim Social Security?
If you can afford to wait to claim, the years before your benefits start are often your cheapest years to convert. With no benefits yet, there's no torpedo. You pay only your bracket rate on each dollar.
Waiting also raises your monthly benefit until 70. Some couples live on savings, convert from 62 or 65 to 70, then claim. The trade-off is that you spend your savings sooner. If you worry about RMDs pushing you into a higher bracket later, these early years are your chance to shrink the IRA first. More on timing in Lowering tax on your RMDs.
Is a bigger conversion ever cheaper per dollar?
Yes, oddly. Once your benefits are 85% taxed, the extra torpedo cost stops. So a larger conversion that goes past the torpedo zone can have a lower average rate than a small one inside it.
That doesn't make a bigger conversion right for you. It still adds more tax in dollars. But it's a reason to run your full numbers. A small "safe" conversion can be your most expensive per dollar. Try Roth conversion tax calculator.
Do Roth withdrawals count toward Social Security taxes later?
No. Your qualified Roth IRA withdrawals aren't taxable income, so they don't count in provisional income. Your traditional IRA withdrawals do.
That's the long-run payoff. If you draw from a Roth, you can keep your provisional income lower and keep more of your benefits untaxed. That can also help a surviving spouse, who files single with lower tax lines. Tax-exempt bond interest is different: it does count in provisional income.
Example: a couple at 67 caught in the torpedo
Pat and Lou are both 67 and file jointly. They get $40,000 a year in Social Security and have a $30,000 pension. With no conversion, $11,100 of their benefits is taxable. Their deductions ($32,200 standard, $3,300 for being 65+, and the $12,000 senior deduction) leave them with no federal income tax.
Between about $4,000 and $27,000 of conversion, each extra $1,000 adds $185 to $222 in tax. That happens even though they're in the 10% and 12% brackets. At $27,000, 85% of their benefits is taxable. After that, each extra $1,000 adds $120.
Say they had converted the same $27,000 before claiming Social Security, with only the pension. Their federal tax would have been about $950 instead of $4,724.
If you have not claimed Social Security yet, your cheapest conversion years may be the ones before you claim.
| Conversion | Taxable Social Security | Federal tax | Average tax on the conversion |
|---|---|---|---|
| $0 | $11,100 | $0 | n/a |
| $10,000 | $19,600 | about $1,210 | 12.1% |
| $27,000 | $34,000 | about $4,724 | 17.5% |
| $60,000 | $34,000 | about $8,684 | 14.5% |
Hypothetical example using 2026 federal brackets and deductions (IRS Rev. Proc. 2025-32 and Schedule 1-A) and the IRS Publication 915 worksheet. It assumes no other income and ignores state tax. Their MAGI stays under the 2026 IRMAA line. Your numbers will differ.
Common questions
Does a Roth conversion count as earned income for Social Security?
No. The earnings test counts wages and self-employment income only. IRA and 401(k) payments, including conversions, don't count.
Can a Roth conversion make my Social Security taxable?
Yes. The conversion adds to provisional income. If that passes $32,000 (joint) or $25,000 (single), part of your benefits becomes taxable.
What is the most of my Social Security that can be taxed?
85%. No matter how high your income, at least 15% of your benefits stays tax-free at the federal level.
Are the provisional income thresholds adjusted for inflation?
No. The $25,000, $32,000, $34,000 and $44,000 lines are written into the tax code and don't change with inflation.
Does the new senior deduction change Social Security taxes?
Not directly. The $6,000 per person deduction for 2025 to 2028 lowers taxable income, but the formula for taxing benefits is unchanged. A conversion can also shrink the deduction once income passes $75,000 (single) or $150,000 (joint).
Do states tax Social Security?
Most states don't, but a few do. Check your state's revenue department for current rules.
Sources
Facts on this page were last checked on November 9, 2026.
- IRS Publication 915, Social Security and Equivalent Railroad Retirement Benefits · Base amounts, 50% and 85% rules, Worksheet 1 used for the example. Read Nov 9, 2026.
- 26 U.S.C. 86, Social Security and tier 1 railroad retirement benefits · Base amounts written into the law with no inflation adjustment. Read Nov 9, 2026.
- SSA POMS RS 02505.240, How major types of remuneration are treated · Payments from an IRA, 401(k) or 403(b) don't count for the earnings test. Read Nov 9, 2026.
- IRS Rev. Proc. 2025-32 (2026 inflation adjustments) · 2026 brackets and standard deduction. Read Nov 9, 2026.
- IRS Schedule 1-A (Form 1040), Additional Deductions · Senior deduction and its phase-out. Read Nov 9, 2026.
Who wrote this
This guide was written and fact-checked by the Secure Retirement Planner editorial team using IRS, CMS and Social Security sources listed above. We update guides when the law or yearly limits change. How we research.