Does Connecticut tax Social Security? Not below $75,000 of AGI ($100,000 joint)

Not if federal AGI is under $75,000 (single) or $100,000 (joint, and head of household). Above that, Connecticut still exempts most of it: its worksheet taxes at most 25% of your benefits. The larger effect is indirect. Connecticut's deduction for pensions and IRA withdrawals phases out as federal AGI rises past the same $75,000 / $100,000, and the taxable part of your benefits counts toward that AGI. In our single example, at $80,000 of IRA withdrawals that costs $3,262 a year; at $100,000, where the deduction is gone either way, the extra is $410.

The rule, in Connecticut's words

The 2025 instructions for line 41: “If you receive Social Security benefits subject to federal income tax, you may reduce or eliminate the amount of your benefits subject to Connecticut income tax.” Above the AGI limit: “Your Social Security benefits are partially exempt from Connecticut income tax if your federal adjusted gross income is above the threshold for your filing status.” The worksheet then takes the smaller of your total benefits and an amount from the federal worksheet and says “Multiply Line C by 25% (.25).” That 25% is the most Connecticut can tax.

What Social Security adds to your Connecticut tax in 2026

Each row compares Connecticut's 2026 income tax with your Social Security and without it, for the same IRA or 401(k) withdrawals. The difference is what your benefits cost you in Connecticut tax, through every rule at once. For the single example, the extra tax starts once IRA withdrawals pass about $57,500; for the couple, about $71,000. It peaks where Social Security pushes AGI into the pension and IRA phase-out, then falls back once the deduction would be gone without it too.

Computed with the same engine and figures as our eight-state tool: federal taxable Social Security from IRS Publication 915, the 2026 federal standard deduction including the extra amount at 65 and the senior deduction, and Connecticut's rules above. No other income, itemized deductions or credits.

Social Security disability benefits

Connecticut's rule applies to all federally taxable Social Security, and the IRS counts disability benefits as Social Security: “Social security benefits include monthly retirement, survivor, and disability benefits.” Disability benefits therefore get the same exemption, with no age requirement.

Pensions and IRA withdrawals

For 2026, 100% of qualifying pension, annuity and traditional IRA income can be deducted if federal AGI is under $75,000 (single) or $100,000 (joint), shrinking in steps to zero at $100,000 / $150,000. For 2025, IRA withdrawals counted at 75%.

2027

We know of no change scheduled for 2027.

The other states that tax Social Security

Colorado, Minnesota, Montana, New Mexico, Rhode Island, Utah, Vermont. All eight side by side are in the eight-state tool, and every state with its own instructions in the all-states tool. How much of your Social Security the federal return taxes is in our taxable Social Security calculator.

Rechecks and changes

• September 30, 2026. First published.

Sources

• Connecticut Department of Revenue Services, 2025 Form CT-1040 instructions (line 41 and the Social Security Benefit Adjustment Worksheet)
• IRS Publication 915, Social Security and Equivalent Railroad Retirement Benefits
• Dollars Ahead, Retirement Tax by State (the eight-state tool and its test cases)

This page shows what published tax rules do to the example incomes. It is not tax, legal or financial advice. For a decision that matters, take your numbers to a professional licensed to advise you.