What is Connecticut's 529 plan deduction limit?

Connecticut lets you deduct up to 5,000 dollars per year as a single filer or 10,000 dollars as a married couple filing jointly for contributions to the CHET 529 plan. Contributions above the cap can be carried forward and deducted in future years.

Does Connecticut offer a credit or a deduction?

Connecticut offers a state income tax deduction, not a credit. The deduction reduces your Connecticut taxable income, so your savings equal the deductible contribution multiplied by your marginal Connecticut income tax rate, not the full contribution amount.

How does the five-year carryforward work?

If you contribute more than the annual cap, Connecticut lets you carry the excess forward and deduct it over the following five years, subject to each year's cap. The calculator shows the deductible amount this year and the excess available for future years.

Do contributions have to go to the Connecticut CHET plan?

Yes. Connecticut limits the deduction to contributions made to its own CHET 529 plan. Contributions to another state's 529 plan generally do not qualify for the Connecticut deduction, so use CHET to capture the state tax benefit.

Is the deduction worth more for high earners?

Yes. Because the benefit is a deduction tied to your marginal rate, a taxpayer in Connecticut's top 6.99 percent bracket saves more per dollar contributed than someone in a lower bracket. Enter your true marginal rate for an accurate estimate.

Connecticut 529 Plan Tax Benefit Calculator

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Connecticut rewards saving for college through its CHET 529 plan with a state income tax deduction — up to 5,000 dollars (single) or 10,000 dollars (married filing jointly) per year, with a five-year carryforward for contributions above the cap. This tool estimates your tax savings.

How it works

The deduction is capped, and your savings equal the deductible amount times your marginal Connecticut rate. Any excess carries forward:

cap            = 5,000 (single) or 10,000 (married filing jointly)
deductible     = min(contribution, cap)
carryforward   = max(0, contribution − cap)
tax savings    = deductible × marginal CT rate

Because it’s a deduction (not a credit), you don’t save the full contribution — you save the tax you would have paid on that income. Only contributions to Connecticut’s own CHET plan qualify.

Example and notes

A married couple contributing 15,000 dollars in Connecticut’s top 6.99% bracket: the deductible amount this year is capped at 10,000, saving 10,000 × 0.0699 = 699 dollars, with the remaining 5,000 available to carry forward into future years. A single filer contributing 4,000 deducts the full amount. Higher marginal rates produce larger savings per dollar. Confirm current limits with the Connecticut DRS and the CHET plan.