Connecticut Income
Tax Rates & Rules

Connecticut has a progressive individual income tax for 2026 with marginal rates from 2% to 6.99%. The calculation is more complex than simply applying a tax bracket because Connecticut also uses personal exemptions, a 2% rate phase-out add-back, tax recapture and personal tax credits based on filing status and Connecticut adjusted gross income.

The official 2026 CT-1040ES calculation starts with federal adjusted gross income, applies Connecticut additions and subtractions, determines Connecticut AGI then uses the state's Tax Calculation Schedule. The final calculation can therefore differ substantially between taxpayers with the same gross income.

Source: Connecticut 2026 Estimated Income Tax Form CT-1040ES

What Are the Connecticut Income Tax Rates for 2026?

Connecticut's 2026 income tax rates are 2%, 4.5%, 5.5%, 6%, 6.5%, 6.9% and 6.99%. The income thresholds vary by filing status.

These are marginal brackets. Moving into a higher bracket does not cause every dollar of taxable income to be taxed at the higher percentage.

Source: Connecticut 2026 Tax Calculation Schedule

How Is Connecticut Income Tax Calculated?

Connecticut income tax is calculated through several steps that can increase or decrease the amount produced by the basic rate table.

• Start with federal adjusted gross income.
• Apply Connecticut additions and subtractions to determine Connecticut adjusted gross income.
• Subtract the applicable Connecticut personal exemption.
• Calculate initial tax using the 2026 marginal rate table.
• Add the 2% rate phase-out amount when required.
• Add tax recapture for higher-income taxpayers when required.
• Apply the personal tax credit percentage.
• Apply other allowable credits, including the credit for taxes paid to qualifying jurisdictions when applicable.

Connecticut AGI - Personal Exemption = Connecticut Taxable Income

Because the exemption, phase-out, recapture and personal tax credit are tied to AGI and filing status, Connecticut's effective tax rate can be different from the marginal rate shown in the bracket table.

Connecticut Personal Exemptions for 2026

Connecticut provides a personal exemption based on filing status and Connecticut AGI. The exemption phases out as AGI rises and eventually reaches zero.

The phase-out occurs in $1,000 AGI increments under the 2026 table. Taxpayers close to a phase-out threshold should use the official Table A rather than estimating the exemption from the maximum amount.

Source: Connecticut 2026 CT-1040ES Table A

What Is the Connecticut 2% Rate Phase-Out Add-Back?

Connecticut gradually removes the benefit of the 2% bracket for higher-income taxpayers through a separate phase-out add-back.

The add-back increases in steps as AGI rises. It is calculated separately from the initial bracket tax and added before the personal tax credit is applied.

Source: Connecticut 2026 Phase-Out Table

What Is Connecticut Tax Recapture?

Connecticut tax recapture increases income tax for higher-income taxpayers by recapturing part of the benefit of lower marginal rates.

For 2026, the recapture table begins above $105,000 of Connecticut AGI for single or married-filing-separately taxpayers, above $210,000 for married filing jointly or qualifying surviving spouse and above $168,000 for head of household. The recapture amount increases as AGI rises.

Source: Connecticut 2026 CT-1040ES Table D

Connecticut Personal Tax Credit

Connecticut also uses a personal tax credit that reduces the tax calculated after the initial tax, phase-out and recapture steps.

The credit is expressed as a decimal percentage in Table E and depends on filing status and Connecticut AGI. At lower qualifying income levels, the table can provide a 75% credit against the calculated amount. The credit then phases down in steps as AGI increases.

This personal tax credit is separate from refundable credits such as the Connecticut Earned Income Tax Credit.

Source: Connecticut 2026 CT-1040ES Table E

Connecticut Earned Income Tax Credit for 2026

Connecticut's Earned Income Tax Credit is a refundable state credit for eligible working taxpayers and families.

Connecticut's EITC equals 40% of the federal EITC. Beginning with taxable years on or after January 1, 2025, eligible CT EITC taxpayers with at least one qualifying child for federal purposes can receive an additional $250.

Because the EITC is refundable, an eligible credit can exceed Connecticut income tax liability and contribute to a refund.

Source: Connecticut Earned Income Tax Credit

Does Connecticut Tax Social Security and Retirement Income?

Connecticut provides state-specific subtractions that can reduce the amount of certain Social Security, pension, annuity and IRA income subject to Connecticut income tax.

DRS states that Social Security benefits are fully exempt when federal AGI is below $75,000 for single or married filing separately and below $100,000 for married filing jointly, qualifying surviving spouse or head of household. Taxpayers above those levels can still qualify for a partial Social Security adjustment under the state worksheet.

Connecticut also provides pension, annuity and IRA subtraction rules for qualifying taxpayers. Eligibility and the amount of the subtraction depend on filing status, AGI and the type of retirement income.

Source: Connecticut Tax Tips for Senior Citizens

Who Must Pay Connecticut Income Tax?

Connecticut income tax applies to full-year residents, part-year residents and nonresidents with Connecticut-source income when the state's filing requirements are met.

Full-year residents generally report Connecticut adjusted gross income on Form CT-1040. Part-year residents and nonresidents generally use Form CT-1040NR/PY and apply the Connecticut-source and apportionment rules.

Connecticut filing status generally follows federal filing status, but special rules apply when spouses have different residency situations.

Connecticut Withholding vs. Final Income Tax

Connecticut wage withholding is a prepayment toward annual income tax and should not be confused with final tax liability.

The amount withheld from each paycheck is based on the state's withholding rules and Form CT-W4 information. The annual income tax return uses the separate CT-1040 calculation with exemptions, phase-out, recapture and credits.

To estimate how Connecticut withholding affects take-home pay, use the Connecticut Paycheck Calculator.

When Are Connecticut Estimated Tax Payments Required?

Connecticut estimated tax payments may be required when expected state tax is not sufficiently covered by withholding or other qualifying prepayments.

For 2026, DRS states that estimated payments are generally required when Connecticut income tax after withholding and any allowed PE Tax Credit is $1,000 or more and expected prepayments are less than the required annual payment.

Source: Connecticut 2026 Individual Income Tax Information

When Is the 2026 Connecticut Income Tax Return Due?

For calendar-year taxpayers, Connecticut income tax returns are generally due on or before April 15 of the following calendar year. That means the 2026 calendar-year return is generally due April 15, 2027, subject to weekend, holiday and any future relief rules.

An extension of time to file does not automatically extend the time to pay tax due. Taxpayers should use the filing-year instructions issued by Connecticut DRS when preparing the return.

Source: Connecticut Tax Tips for Senior Citizens