What is Connecticut Income Tax? Rates & Tax Brackets

Updated for tax year 2025.

If you live or work in Connecticut, you’ll likely need to file a Connecticut state income tax return along with your federal return. Connecticut uses a progressive income tax structure with seven tax rates that depend on your filing status and Connecticut taxable income.

This guide explains Connecticut’s 2025 income tax rates and brackets, personal exemption, available subtractions and credits, and the updates for the current tax year. When you’re ready to file, TaxAct® automatically applies Connecticut’s tax rules to help you accurately prepare your Connecticut return alongside your federal return.

What is the Connecticut state income tax?

Connecticut state income tax is a tax on income earned by individuals. It is collected by the Connecticut Department of Revenue Services (DRS) and helps fund state services.

Connecticut uses a progressive income tax structure with seven rates for tax year 2025 — from 2% to 6.99% — depending on your filing status and Connecticut taxable income. Connecticut taxable income is generally based on your Connecticut adjusted gross income minus your personal exemption, calculated using the state’s Tax Calculation Schedule.

Connecticut income tax rates and tax brackets

To estimate your Connecticut tax bill or refund, it helps to understand the state’s income tax brackets. Here is a look at Connecticut’s 2025 income tax brackets by filing status, carried from the live Connecticut refund page:

Tax Rate	Singles and Married Filing Separately	Married Filing Jointly & Surviving Spouse
2%	$0–$10,000	$0–$20,000
4.5%	$10,001–$50,000	$20,001–$100,000
5.5%	$50,001–$100,000	$100,001–$200,000
6%	$100,001–$200,000	$200,001–$400,000
6.5%	$200,001–$250,000	$400,001–$500,000
6.9%	$250,001–$500,000	$500,001–$1,000,000
6.99%	$500,001 and above	$1,000,001 and above

If you need more information on how federal tax brackets work, you can use our tax bracket calculator for federal taxes. Head of household filers use a separate bracket schedule in Connecticut’s official Tax Calculation Schedule. See Table B, Initial Tax Calculation for official 2025 rate information.

Connecticut standard deduction

Connecticut does not use a federal-style standard deduction on Form CT-1040. Instead, Connecticut allows a personal exemption (Table A on the Tax Calculation Schedule) that reduces Connecticut adjusted gross income before tax is calculated.

Connecticut exemptions

Qualifying taxpayers in Connecticut can claim a personal exemption on their state income tax return. Connecticut also offers subtractions and tax credits to residents who qualify, such as partial exemptions for Social Security benefits, pension and annuity income subtractions, and the property tax credit on Schedule 3 for qualifying homeowners.

The personal exemption amount varies based on filing status and Connecticut adjusted gross income. Qualifying taxpayers may receive a maximum personal exemption of up to $15,000 for single filers and $24,000 for married filing jointly, but the exemption phases down as income increases and may be reduced to zero at higher income levels. If your Connecticut adjusted gross income is below certain thresholds — $15,000 for single filers, $12,000 for married filing separately, $19,000 for head of household, or $24,000 for married filing jointly or qualifying surviving spouse — you generally owe no Connecticut income tax.

Connecticut taxpayers may also qualify for credits such as the credit for income taxes paid to qualifying jurisdictions and various other personal tax credits shown on Table E of the Tax Calculation Schedule. See the 2025 CT-1040 instructions for eligibility and limits.

Connecticut tax changes for 2025

For tax year 2025, Connecticut continues to use its seven-bracket progressive rate structure with a top marginal rate of 6.99%. Connecticut generally conforms to the Internal Revenue Code on a rolling basis, with state-specific additions and subtractions noted in the CT-1040 instructions.

Connecticut’s tax calculation also includes a 2% tax rate phase-out add-back (Table C) for higher-income taxpayers, which can increase tax above the initial bracket calculation. See the 2025 Tax Calculation Schedule and CT-1040 instructions for a full list of 2025 tax rules and credits.

FAQs

Does Connecticut have a state income tax?

Yes, Connecticut has a state income tax. Connecticut uses a progressive income tax structure with seven tax rates for tax year 2025, ranging from 2% to 6.99% depending on your filing status and Connecticut taxable income.

What is the Connecticut income tax rate?

Connecticut’s 2025 income tax rates are 2%, 4.5%, 5.5%, 6%, 6.5%, 6.9%, and 6.99%. The rate that applies to you depends on your filing status and Connecticut taxable income. The top marginal rate for 2025 is 6.99%.

What are the Connecticut income tax brackets for 2025?

Connecticut’s 2025 tax brackets differ by filing status. Single and married filing separately filers use one set of income ranges, while married filing jointly and qualifying surviving spouse filers use another. Head of household filers use a separate bracket schedule. See the Connecticut income tax brackets table above.

How does Connecticut state income tax work?

Connecticut state income tax generally starts with your federal adjusted gross income, then applies Connecticut additions and subtractions to arrive at Connecticut adjusted gross income. You subtract your personal exemption, calculate tax using Connecticut’s rate schedule, and may owe additional amounts such as the 2% tax rate phase-out add-back before credits are applied.

Do I have to file a Connecticut state tax return?

You may need to file a Connecticut state tax return if you are a Connecticut resident whose Connecticut adjusted gross income exceeds your filing threshold, or if you are a part-year resident or nonresident with Connecticut-source income. Filing requirements depend on your income, residency, and other factors, so check Connecticut Department of Revenue Services guidance for your situation.

What is the Connecticut standard deduction for 2025?

Connecticut does not use a federal-style standard deduction. Instead, Connecticut allows a personal exemption that varies based on filing status and Connecticut adjusted gross income. Maximum personal exemption amounts are up to $15,000 for single filers and $24,000 for married filing jointly, but the exemption phases down as income increases.

How much is Connecticut state income tax?

There isn’t one Connecticut state income tax amount that applies to everyone. How much you owe depends on your Connecticut adjusted gross income, personal exemption, filing status, available subtractions and credits, and which tax rate bracket applies. Use the brackets above and the Connecticut Tax Calculation Schedule as a starting point.

Why is my Connecticut tax return different from my federal return?

Connecticut generally follows federal tax law through rolling conformity to the Internal Revenue Code, but Connecticut has its own additions, subtractions, personal exemption rules, and credits that can make your Connecticut adjusted gross income and tax liability different from your federal return.

The good news is that our tax software automatically applies Connecticut’s current tax rules when preparing your state return, so you don’t have to calculate these differences yourself.

For more information, visit the Connecticut Department of Revenue Services. If you’d like to learn more about recent federal tax law changes, see our OBBB tax changes guide.

The bottom line

Connecticut has a progressive state income tax for 2025 with rates from 2% to 6.99%, depending on your filing status and Connecticut taxable income. Knowing the brackets, how the personal exemption works, and available subtractions and credits can help you estimate what you may owe or get back.

When you’re ready to file, TaxAct can help you prepare your federal and Connecticut returns in one place so you can file with confidence.

Already filed your taxes and waiting for your refund? Learn more about where your Connecticut state tax refund is.

This article is for informational purposes only and not legal or financial advice.

All TaxAct offers, products and services are subject to applicable terms and conditions.

The OBBB is now also being referred to by lawmakers as the Working Families Tax Cut Act. You may see one or both names used here, but they refer to the same set of tax changes.

Citations

Connecticut Department of Revenue Services. “Resident Income Tax Information.” Accessed 14 Aug. 2026.
Connecticut Department of Revenue Services. “2025 Tax Calculation Schedule (CT-1040-TCS).” Accessed 14 Aug. 2026.
Connecticut Department of Revenue Services. “2025 CT-1040 Instructions.” Accessed 14 Aug. 2026.