What Is the Income Tax Rate in Connecticut?

Connecticut imposes a state income tax on its residents and those earning income within its borders. This tax system is progressive, meaning higher earners pay a larger percentage of their income in taxes.

Connecticut Income Tax Rates and Brackets

Connecticut’s income tax system features seven progressive tax brackets for the 2024 tax year, reported on returns filed in 2025. The tax rates range from 2% to 6.99%. This progressive structure means different portions of income are taxed at varying rates, with higher income segments subject to higher marginal rates.

For single filers:
The first $10,000 of taxable income is taxed at 2%.
Income between $10,001 and $50,000 is taxed at 4.5%.
Income from $50,001 to $100,000 is taxed at 5.5%.
Income from $100,001 to $200,000 is taxed at 6%.
Taxable income between $200,001 and $250,000 is taxed at 6.5%.
Income from $250,001 to $500,000 is taxed at 6.9%.
Any taxable income exceeding $500,000 is taxed at 6.99%.

For married couples filing jointly, the income brackets are generally doubled, while the tax rates remain the same. For instance, the first $20,000 of taxable income is taxed at 2%, and income from $20,001 to $100,000 is taxed at 4.5%. This scaling continues through all seven brackets, ensuring married filers receive a corresponding adjustment to their income thresholds.

Calculating Connecticut Taxable Income

The process of determining Connecticut taxable income begins with a taxpayer’s federal adjusted gross income (AGI). This federal AGI serves as the baseline, which is then modified by specific Connecticut additions and subtractions to arrive at the Connecticut Adjusted Gross Income (CT AGI).

Common additions to federal AGI for Connecticut purposes include interest income from state and local government obligations outside of Connecticut, which is federally tax-exempt. Other additions may involve certain bonus depreciation amounts or Connecticut income tax deducted on the federal return. Conversely, taxpayers can make several subtractions from federal AGI.

These subtractions may include certain pension and annuity income, contributions to a Connecticut Higher Education Trust (CHET) account, and gains from the sale of Connecticut state and local government bonds. Connecticut also offers personal exemptions which reduce the taxable income. For instance, a single filer might have a personal exemption of up to $15,000, while married couples filing jointly can claim up to $24,000. These exemptions, however, begin to phase out as CT AGI rises above certain thresholds, such as $30,000 for single filers and $48,000 for married filing jointly, eventually being eliminated for higher earners.

Connecticut also provides various tax credits that can directly reduce a taxpayer’s final tax liability, rather than reducing taxable income. One such credit is the Property Tax Credit, which can be up to $300 for eligible Connecticut homeowners who pay property taxes on their primary residence or a registered motor vehicle. Eligibility for this credit is subject to income limitations and it phases out for higher incomes. Another significant credit is the Connecticut Earned Income Tax Credit (CT EITC), which is 40% of the federal Earned Income Tax Credit for qualifying residents. To qualify for the CT EITC, individuals must meet federal EITC eligibility requirements and be full-year Connecticut residents.

Connecticut Residency and Filing Requirements

Connecticut defines residency for income tax purposes through two primary tests: domicile and statutory residency. An individual is considered a resident if Connecticut was their permanent legal residence, or domicile, for the entire tax year. Even if one’s domicile is elsewhere, an individual can be considered a statutory resident if they maintain a permanent place of abode in Connecticut for the entire tax year and spend more than 183 days in the state during that year.

Full-year residents are taxed on all income, regardless of where it was earned, including income from sources both within and outside Connecticut. Part-year residents are individuals who moved into or out of Connecticut during the tax year. They are typically taxed on income earned while they were residents of Connecticut, and on any Connecticut-source income earned during their non-resident period. Non-residents are taxed only on income derived from Connecticut sources, such as wages from a Connecticut employer, business income from activities conducted in the state, or rental income from Connecticut property.

Filing requirements for a Connecticut income tax return are triggered by various conditions, including meeting certain gross income thresholds. For the 2024 tax year, single filers must file if their gross income is at least $15,000. For married couples filing jointly, the threshold is $24,000. Other thresholds include $12,000 for married filing separately and $19,000 for head of household.

A Connecticut return must also be filed if Connecticut income tax was withheld, estimated tax payments were made, a federal alternative minimum tax liability exists, or if a taxpayer is claiming the Connecticut Earned Income Tax Credit or had a Pass-Through Entity Tax Credit.