How much of your Social Security is taxable
Enter the benefits from your SSA-1099, your other income and your filing status: the tool follows the IRS worksheet line by line.
Checked by Radif Partners · Editorial policy · How we calculate
Federal income tax reaches Social Security benefits through provisional income: your other income, tax-exempt interest included, plus half of your benefits. For a single filer, nothing is taxable while that total stays at or under $25,000; up to 50% of benefits becomes taxable above it and up to 85% above $34,000. For a married couple filing jointly the two thresholds are $32,000 and $44,000. Married filing separately and living together at any time in the year, the threshold is zero. The thresholds are written in section 86 of the Internal Revenue Code and are not indexed to inflation, so more retirees cross them every year. With $24,000 of benefits and $25,000 of other income, a single filer has $37,000 of provisional income and $7,050 of taxable benefits, 29.4%. Never more than 85% of benefits is taxable. The extra $6,000 deduction for people 65 and older (tax years 2025 to 2028) lowers taxable income, not this share.
Taxable part of your benefits
$7,700
27.5% of $28,000 goes on line 6b of Form 1040
| Provisional income (other income + half of benefits) | $46,000 |
| First base (50% zone starts) | $32,000 |
| Second base (85% zone starts) | $44,000 |
| Zone you are in | 85% zone |
The taxable amount is added to your other income and taxed at your own federal rate: this is not the tax itself. Worksheet 1 of IRS Publication 915, without the IRA-deduction and lump-sum special cases.
Provisional income, the number that decides
The IRS does not tax benefits on their own. It builds a test figure: adjusted gross income without the benefits, plus tax-exempt interest, plus half the benefits. That is Worksheet 1 of IRS Publication 915, which the tool reproduces. Tax-exempt municipal bond interest is not taxed itself, but it counts here and can make benefits taxable. Taxable pensions, IRA withdrawals, wages, interest, dividends and capital gains all count.
| Other income | Single, $24,000 benefits: taxable | Share | Joint, $40,000 benefits: taxable | Share |
|---|---|---|---|---|
| $10,000 | $0 | 0.0% | $0 | 0.0% |
| $15,000 | $1,000 | 4.2% | $1,500 | 3.8% |
| $20,000 | $3,500 | 14.6% | $4,000 | 10.0% |
| $25,000 | $7,050 | 29.4% | $6,850 | 17.1% |
| $30,000 | $11,300 | 47.1% | $11,100 | 27.8% |
| $40,000 | $19,800 | 82.5% | $19,600 | 49.0% |
| $50,000 | $20,400 | 85.0% | $28,100 | 70.3% |
| $60,000 | $20,400 | 85.0% | $34,000 | 85.0% |
Two tiers, then a cap
Between the first and second threshold, taxable benefits equal half of the provisional income above the first threshold, capped at half the benefits. Above the second threshold, 85% of the excess is added to a fixed amount from the first tier. The result can never exceed 85% of benefits, which is why the share in the table stops at 85.0% however high the other income. A single filer with $24,000 of benefits reaches that ceiling at $45,000 of other income: $20,400 taxable. With $15,000 only, the first tier applies and $1,000 is taxable.
The taxable amount is not a tax. It is added to your other income and taxed at your marginal rate. A couple filing jointly with $40,000 of benefits and $30,000 of other income reports $11,100 of taxable benefits on line 6b of Form 1040.
Thresholds that never move
The $25,000 and $32,000 amounts of the first tier and the $34,000 and $44,000 amounts of the second are written as fixed dollars in section 86 of the Internal Revenue Code, with no indexing clause, and Publication 915 repeats them unchanged. Benefits, meanwhile, rise every January with the cost-of-living adjustment, 2.8% for 2026 (SSA notice). The effect is a slow increase in the share of retirees who pay tax on part of their benefits.
The senior deduction does not change the taxable share
For tax years 2025 through 2028, people 65 or older by the end of the year can deduct an extra $6,000, or $12,000 for a couple filing jointly when both qualify, as described by the IRS. Married people must file jointly to claim it, and it phases out above $75,000 of modified AGI ($150,000 joint). It reduces taxable income after the worksheet above, so the taxable part of your benefits is the same with or without it; only the tax computed on the total can fall.
Other situations
Nonresident aliens are taxed differently: 85.0% of benefits is taxed at 30%, unless a tax treaty exempts or reduces it, which is the case for residents of Canada, Egypt, Germany, Ireland, Israel, Italy, Japan, Romania and the United Kingdom. See Social Security abroad. The Part B page covers the $202.90 monthly premium, a separate question from income tax. State income taxes follow their own rules and are not computed here. Working while collecting raises provisional income and may also trigger the earnings test.