Taxes on Social Security benefits start at a combined income of $25,000 for a single filer and $32,000 for a couple filing jointly, and those thresholds have not moved since they were written into law in 1983, according to the Social Security Administration (SSA). They are not indexed to inflation, which means every cost-of-living adjustment pushes more beneficiaries above them. The 2.8% COLA applied in January 2026 did exactly that, without a single word of the tax code changing.
It is the quietest tax increase in the federal system: automatic, annual, and invisible until the return is filed.
What “combined income” means
The figure the IRS uses is not the same as taxable income. Combined income, sometimes called provisional income, is:
- Adjusted gross income, plus
- Any tax-exempt interest, plus
- Half of the Social Security benefits received that year.
Only half the benefit counts in the test, which is why a retiree can be well above $25,000 in gross income and still fall below the threshold, or the reverse.
The two brackets
Nothing is taxed below the first threshold. Above it, a share of the benefit becomes taxable income, not a percentage taken from the check:
- Single filers: up to 50% of benefits taxable between $25,000 and $34,000; up to 85% above $34,000.
- Joint filers: up to 50% taxable between $32,000 and $44,000; up to 85% above $44,000.
The distinction matters. An 85% figure does not mean 85% of the benefit is taken. It means up to 85% of it is added to taxable income and then taxed at the person’s ordinary rate.
Why 1983 and 1993 still govern 2026
The $25,000 and $32,000 thresholds date from the 1983 reform. The second tier, at $34,000 and $44,000, arrived in 1993. Neither was indexed.
When they were set, a small minority of beneficiaries were affected. Four decades of COLAs later, the same nominal figures capture a far larger share of retirees, including many whose real income has not risen at all.
What can be done about it
The lever most retirees have is the timing and source of other income, since only some of it counts. Withdrawals from a Roth account do not enter adjusted gross income, while withdrawals from a traditional 401(k) or IRA do. Tax-exempt municipal interest, by contrast, is added back into the combined income calculation despite being exempt elsewhere.
Beneficiaries can also ask the SSA to withhold federal tax from the payment itself, at 7%, 10%, 12% or 22%, using form W-4V. It avoids a bill in April at the cost of a smaller monthly deposit.
The state layer sits on top
This is federal tax. Separately, eight states still tax Social Security income in some form, most with generous thresholds of their own. California, Florida and Texas, the three states with the most beneficiaries, are not among them.
Between the federal thresholds frozen since 1983 and the $202.90 Medicare Part B premium deducted before the money arrives, the gap between the benefit the SSA announces and the amount a retiree can actually spend is wider than the headline figures suggest.
