Deductions & credits
How much of a client's Social Security is taxable?
A taxable Social Security calculator that applies the IRS provisional-income method, so retirees can see why some of their benefit is taxed and how other income changes that.
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How much of Social Security is taxable?
It depends on provisional income: other income plus tax-exempt interest plus half of the benefits. Below the first threshold, none is taxable; above it, up to 50%; above the second threshold, up to 85%. The 2026 rule: up to 85% taxable; thresholds $25,000 / $34,000 (single) and $32,000 / $44,000 (joint)2026 · IRS. At least 15% of benefits always stays federally tax-free.
February, when the SSA-1099 arrives
New retirees are often surprised that benefits are taxable at all, and the SSA-1099 in their mailbox triggers the search. Others notice in the fall that an IRA withdrawal or a part-time job made more of their benefit taxable. Both want to understand the mechanism before deciding how to draw income next year.
What the client types into a search box
“why do I have to pay tax on my social security”
How a client works through it
Enter annual benefits
The total from box 5 of the SSA-1099, or an estimate for the coming year.
Enter other income
Pensions, IRA withdrawals, wages, interest and dividends, including tax-exempt interest.
Choose filing status
The thresholds differ for single and joint filers.
See the taxable share
Provisional income, the taxable amount, the tax-free portion and the percentage taxable.
What lands in your inbox
When a client asks your firm to review the result, the request arrives as a contact record with their inputs and results attached, by email and, on paid plans, by webhook to your CRM.
Received
Annual benefits, other income and filing status show where the client sits relative to the thresholds. Provisional income just above a threshold means a client whose withdrawal strategy matters. Large other income with modest benefits suggests IRA withdrawals or pensions to plan around.
What does provisional income tell a retiree?
Provisional Income is the figure the IRS compares with the thresholds. Taxable Social Security is the part of benefits added to taxable income; the Tax-Free Portion is the rest. % Taxable shows the share, which can never exceed 85%.
The number to watch is how fast % Taxable rises when Other Income goes up. Running the calculator twice, once with and once without a planned IRA withdrawal, shows the client the hidden cost of that withdrawal.
Results shown: Taxable Social Security · Provisional Income · Tax-Free Portion · Social Security Benefits · % Taxable.
A single filer just over the first threshold
A single retiree receives $24,000 of benefits and has $16,000 of other income. Provisional income is $16,000 + $12,000 = $28,000, which is $3,000 above the $25,000 base. Half of that excess, $1,500, is taxable, because the client is still below the $34,000 second threshold. The other $22,500 of benefits stays tax-free.
Why is this calculator valuable to firms with retired clients?
The taxation of benefits is where retirement income planning creates real tax savings. Each extra dollar of IRA withdrawal can pull more benefits into taxable income, raising the effective marginal rate well above the bracket. Clients who see the mechanism understand why a firm suggests drawing from a Roth, timing a conversion or spreading withdrawals.
It's also a reliable February search, which brings retirees to your site at the start of filing season.
Follow-ups this request opens
- Plan the order of withdrawals between IRA, Roth and taxable accounts
- Estimate the true marginal rate on IRA withdrawals in the benefit-taxation zone
- Review federal withholding on Social Security using Form W-4V
- Evaluate a partial Roth conversion before benefits start
What this calculator leaves out
- Uses the federal worksheet only; state taxation of benefits varies.
- Special cases such as lump-sum back payments are not modeled.
- Married filing separately while living together has a zero base amount, which the calculator applies but does not explain in detail.
- Does not calculate the income tax due on the taxable portion.
Platform disclaimer shown under the calculator: Estimates only. Uses the IRS provisional-income worksheet thresholds; up to 85% of benefits can be taxable. State rules and special cases differ. Not tax advice.
Compliance note for firms
Showing how benefits are taxed is education. Recommending a withdrawal sequence or Roth conversion based on it is written advice under Circular 230 §10.37 for tax practitioners, and for advisers it may form part of a financial plan with its own disclosure requirements.
Not legal advice. See our disclaimer and the guide to compliance for client calculators.
2026 figures this page relies on
| Figure | Value | Tax year | Source |
|---|---|---|---|
| Taxable share of Social Security benefits and provisional-income thresholds | up to 85% taxable; thresholds $25,000 / $34,000 (single) and $32,000 / $44,000 (joint) | 2026 | IRS (Publication 915 worksheet) |
The same values drive the calculator. Full list on the 2026 figures page.
Terms your client sees in the calculator
These definitions appear in the calculator's collapsible Definitions block, so clients don't have to call to ask what a label means.
- Provisional income
- The IRS measure used to decide whether benefits are taxable: your other income (AGI excluding Social Security) plus tax-exempt interest plus half of your Social Security benefits. The calculator compares this figure with the base amounts for your filing status to determine how much of your benefits enter taxable income.
- Taxable Social Security
- The dollar amount of your benefits that is added to taxable income. It is not a tax bill; your tax is that amount taxed at your own bracket. Up to 85% of benefits can be taxable under the IRS worksheet, as applied here for 2026. Below the first base amount, none of your benefits is taxable.
- Base amounts
- The provisional-income thresholds where benefits start to become taxable and where the higher inclusion rate begins: $25,000 and $34,000 for single filers, $32,000 and $44,000 for joint filers, and $0 if married filing separately and living with your spouse (IRS worksheet, as used here for 2026). Income above each threshold increases the taxable portion.
- Filing status
- The category you file your federal return under, such as single or married filing jointly. In this calculator it sets which base amounts apply. Married couples filing separately who lived together at any time during the year have a $0 base amount, so their benefits are taxable from the first dollar of provisional income.
- Other income
- Your taxable income from sources other than Social Security, such as wages, pensions, IRA withdrawals, interest and dividends, plus any tax-exempt interest. This is usually the driver of the result: each additional dollar of other income can make more of your benefits taxable once you are past the first base amount.
- Tax-exempt interest
- Interest that is not subject to federal income tax, most commonly from municipal bonds. Although it is not taxed itself, the IRS counts it in provisional income. That means municipal bond interest can increase the share of your Social Security that is taxable, which is why this calculator asks you to include it with other income.
In our glossary: Provisional income · Full retirement age
Taxable Social Security Benefits calculator: questions from firms and clients
What is provisional income?
Other income plus tax-exempt interest plus half of Social Security benefits. It is the figure compared with the thresholds to decide how much of the benefit is taxable.
What are the thresholds?
up to 85% taxable; thresholds $25,000 / $34,000 (single) and $32,000 / $44,000 (joint)2026 · IRS. They are not indexed for inflation, which is why more retirees pay tax on benefits each year.
Can all of my Social Security be taxable?
No. At most 85% of benefits is taxable, so at least 15% is always federally tax-free.
Does tax-exempt municipal bond interest count?
Yes. It is included in provisional income even though it is not taxable itself, which surprises many retirees.
Do states tax Social Security?
A few do. The calculator covers federal rules only.
How can a retiree reduce the taxable portion?
By managing other income: Roth withdrawals don't count toward provisional income, and qualified charitable distributions can reduce it. That is planning work for the firm.
Should clients withhold tax from benefits?
Many should. Form W-4V lets them choose a withholding percentage. The firm can recommend the right one.
Which plan includes this calculator?
Network, with the other tax calculators. See pricing.
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