How much is Connecticut income tax?
Connecticut income tax at 3 levels of Connecticut taxable income — what is left after Connecticut's own deductions and exemptions. Local income taxes are not included.
| Taxable income | Single | Married filing jointly |
|---|---|---|
| $50,000 | $1,8003.6% effective · 4.95% marginal | $1,5753.1% effective · 4.05% marginal |
| $100,000 | $4,9755.0% effective · 6% marginal | $3,9203.9% effective · 5.39% marginal |
| $250,000 | $15,4006.2% effective · 6.9% marginal | $13,2005.3% effective · 6% marginal |
These figures include a rule from Connecticut's law that the bracket table cannot show: Conn. Gen. Stat. §12-703(a)(1), (a)(2)(I), (b), (c) · CT DRS Form CT-1040ES (Rev. 01/26) and Form CT-1040 TCS (Rev. 12/25), Table E.
These figures include a rule from Connecticut's law that the bracket table cannot show: Conn. Gen. Stat. §12-700(a)(10)(A)(ii), (B)(ii), (C)(ii), (D)(ii) · CT DRS Form CT-1040ES (Rev. 01/26) and Form CT-1040 TCS (Rev. 12/25), Table C.
These figures include a rule from Connecticut's law that the bracket table cannot show: Conn. Gen. Stat. §12-700(a)(10)(A)(iii)–(v), (B)(iii)–(v), (C)(iii)–(v), (D)(iii)–(v) · CT DRS Form CT-1040ES (Rev. 01/26) and Form CT-1040 TCS (Rev. 12/25), Table D.
Run your own Connecticut numbersWhat are Connecticut's income tax brackets for 2026?
| Taxable income | Rate |
|---|---|
| Up to $10,000 | 2% |
| Over $10,000 up to $50,000 | 4.5% |
| Over $50,000 up to $100,000 | 5.5% |
| Over $100,000 up to $200,000 | 6% |
| Over $200,000 up to $250,000 | 6.5% |
| Over $250,000 up to $500,000 | 6.9% |
| Over $500,000 | 6.99% |
| Taxable income | Rate |
|---|---|
| Up to $20,000 | 2% |
| Over $20,000 up to $100,000 | 4.5% |
| Over $100,000 up to $200,000 | 5.5% |
| Over $200,000 up to $400,000 | 6% |
| Over $400,000 up to $500,000 | 6.5% |
| Over $500,000 up to $1,000,000 | 6.9% |
| Over $1,000,000 | 6.99% |
Source: Conn. Gen. Stat. §12-700, checked September 17, 2026.
Can you deduct Connecticut income tax on your federal return?
The federal deduction for state and local taxes (SALT) is capped at $40,400 for 2026 — $20,200 if married filing separately — and the cap shrinks toward $10,000 once modified AGI passes $505,000. A single filer with $250,000 of Connecticut taxable income owes about $15,400 in Connecticut income tax — 38% of that cap before any property tax.
SALT cap workaroundsDoes Connecticut have a pass-through entity tax (PTET)?
Yes. A partnership or S corporation can elect to pay Connecticut income tax at the entity level. The business deducts it federally, so that state tax is not limited by the SALT cap, and the owners claim a Connecticut credit or exclusion for it. Deductsy's plan treats March 15 as the Connecticut election or first-payment deadline; it is approximate, so confirm it with Connecticut before relying on it.
PTET savings calculatorWhen are Connecticut estimated tax payments due?
Connecticut estimated tax is due April 15, June 15, September 15 and January 15 of the following year, in 4 equal instalments. Those are the same dates as the federal schedule. Source: Form CT-1040ES, 2026 Estimated Connecticut Income Tax Payment Coupon for Individuals (Rev. 01/26); Conn. Gen. Stat. §12-722(d)(1).
Safe-harbor calculatorWhat is the penalty for underpaying Connecticut estimated tax?
Connecticut charges 1% a month — 12% a year — on an underpaid instalment. Paying at least 90% of this year's tax or 100% of last year's on time avoids it. No estimated payments are required if you expect to owe less than $1,000. Source: Form CT-1040ES, 2026 Estimated Connecticut Income Tax Payment Coupon for Individuals (Rev. 01/26).
Are HSA contributions deductible in Connecticut?
Yes. Connecticut follows the federal treatment, so an HSA contribution — up to $4,400 with self-only coverage or $8,750 with family coverage for 2026 — lowers Connecticut taxable income as well as federal.
Does Connecticut give a tax break for 529 plan contributions?
Yes. Connecticut lets you deduct up to $5,000 a year of contributions to Connecticut's own 529 plan ($10,000 on a joint return). Income limits, per-beneficiary caps and carryforwards differ by state, so check the plan's rules.
529 plan tax savings calculatorDoes Connecticut take a disability or paid-leave tax out of paychecks?
Yes. Connecticut employees pay CT Paid Leave through payroll: 0.5% of wages for 2026, on wages up to $184,500. It comes out on top of federal payroll taxes and Connecticut income tax withholding.
What is the property tax rate in Connecticut?
Connecticut's average effective property tax rate is 1.81% — the 3rd highest of 51 jurisdictions and 2.0 times the national average of 0.9%. That is about $1,810 a year for every $100,000 of home value; the rate varies widely by county and school district.
Itemize or take the standard deduction?How much does an LLC cost to keep in Connecticut each year?
Deductsy budgets about $80 a year for a Connecticut LLC — the annual report fee or minimum franchise tax, with a fee due every two years counted at half. Fees change, so confirm with Connecticut's business filing office.
Connecticut S-corp tax calculatorHow do Connecticut taxes compare with neighboring states?
| State | Top income tax rate | Income tax on $100,000 (single) | Property tax (avg) |
|---|---|---|---|
| Connecticut | 6.99% | $4,975 | 1.81% |
| Massachusetts | 9% | $5,000 | 1.07% |
| New York | 10.9% | $5,336 | 1.55% |
| Rhode Island | 5.99% | $4,016 | 1.21% |
On $100,000 of taxable income a single filer's Connecticut income tax is $4,975 — more than in 1 of 3 neighboring states. The lowest is Rhode Island at $4,016; the highest is New York at $5,336. Connecticut's average property tax rate is higher than in all 3.
Income tax is each state's own tax on the same state taxable income; local income taxes are not included.
Tax moves that matter most for Connecticut
If you own an S corporation, partnership or multi-member LLC, Connecticut's PTET election moves the Connecticut income tax on that profit to the business, where it is deductible federally and outside the SALT cap.
That is the 3rd highest of 51 and 2.0 times the national average, so property tax does much of the work of filling the SALT cap. Bunching two years of property tax into one can push itemized deductions past the standard deduction in alternate years.
An S-corp election can cut self-employment tax once profit is large enough to pay yourself a reasonable salary and still cover payroll and filing costs. The Connecticut calculator adds Connecticut's own entity fees and taxes to that breakeven.
With 1099 income, a Solo 401(k) can take up to $72,000 a year (2026) — usually more than a SEP-IRA at the same income. Contributions lower both federal and Connecticut income tax.
Run your Connecticut numbers
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