Connecticut State Tax Deductions

Connecticut’s personal income tax system differs significantly from the federal model.

The state does not offer a standard deduction or traditional itemized deductions.

Instead, taxpayers begin their return with Federal Adjusted Gross Income (AGI) and apply a series of Connecticut-specific subtractions (deductions) and tax credits to determine their final tax liability.

This structure makes understanding Connecticut’s rules especially important, as many benefits depend on income thresholds and specific eligibility requirements.

Connecticut Subtractions From Income (Deductions)

Connecticut deductions are formally known as “subtractions from income.” These amounts are subtracted from your Federal AGI to arrive at your Connecticut AGI, which is then used to calculate state tax.

Retirement Income Deductions

Connecticut provides some of the most generous retirement income exclusions in the country, particularly for middle-income taxpayers.

• Pensions and Annuities:
  For the 2025 tax year, taxpayers with Federal AGI below $75,000 (single, married filing separately, or head of household) or $100,000 (married filing jointly) may deduct 100% of qualifying pension and annuity income.
• IRA Distributions:
  Eligible taxpayers may deduct 75% of non-Roth IRA distributions in 2025. This exclusion is scheduled to increase to 100% beginning in 2026.
• Social Security Benefits:
  Taxpayers below the same AGI thresholds—$75,000 (single/MFS) or $100,000 (MFJ/HOH)—may deduct 100% of Social Security benefits from Connecticut income.
• Military and Railroad Retirement Income:
  100% of military retirement pay and Tier 1 and Tier 2 railroad retirement benefits are fully deductible.
• Connecticut Teachers’ Retirement Income:
  50% of income received from the Connecticut Teachers’ Retirement Board is deductible.

CHET College Savings Contributions

Contributions to a Connecticut Higher Education Trust (CHET) account are deductible:

• Up to $5,000 for single filers
• Up to $10,000 for married couples filing jointly

Exempt Dividends

Dividends from qualifying mutual funds that are attributable to U.S. government obligations may be deducted from Connecticut income.

Connecticut Tax Credits

Unlike deductions, tax credits reduce your actual tax bill, dollar for dollar.

Personal Exemption Credit

Connecticut treats its personal exemption as a credit rather than a deduction. The credit phases out as income rises. The maximum exemption is:

• Up to $15,000 for single filers
• Up to $24,000 for married couples filing jointly

Property Tax Credit

Eligible homeowners or vehicle owners may claim a property tax credit of up to $300, depending on income.

Connecticut Earned Income Tax Credit (CT EITC)

Taxpayers who qualify for the federal Earned Income Tax Credit may also claim a Connecticut credit equal to 40% of their federal EITC.

Personal Tax Credit

This credit reduces tax liability by 1% to 75%, depending on income level, and is automatically calculated on the return.

Credit for Taxes Paid to Other Jurisdictions

Residents who pay income tax to another state on the same income may claim a credit to prevent double taxation.

Why Electronic Filing Is Recommended

Because Connecticut’s tax system relies heavily on income thresholds, phased deductions, and credit calculations, electronic filing (e-filing) is highly recommended.

E-filing:

• Automatically applies income-based phaseouts
• Correctly calculates retirement income exclusions
• Ensures credits are applied in the proper order
• Reduces math and reporting errors
• Speeds processing and refunds

Using approved tax software or a professional e-file provider helps ensure your Connecticut return is accurate, compliant, and optimized for all available deductions and credits.