Connecticut Estate Tax: Threshold & Rates

A flat rate is the easy part of the story. A decade of rising thresholds and a genuinely unusual gift-tax cap are the rest of it.

Conn. Gen. Stat. §12-391, §12-392

Quick answer: exemption equals the federal basic exclusion amount ($15,000,000 for 2026), then a flat 12% above it, capped at $15,000,000 total combined with any Connecticut gift tax already paid. Run your own numbers in the Connecticut estate tax calculator.

A flat rate is genuinely recent

The $15,000,000 cap covers gifts too

Connecticut's cap isn't just on the estate tax alone — it's a combined lifetime limit shared with the state's own gift tax. Any Connecticut gift tax the decedent (or, in certain cases, their spouse) already paid on gifts that are includable in the decedent's estate reduces this $15,000,000 ceiling, though never below zero.

A narrow credit for Connecticut private investment funds

A decedent who invested in a qualifying Connecticut private investment fund or fund of funds for at least ten years can have their estate tax reduced by half the amount invested, up to $5,000,000 per decedent — subject to an aggregate $30,000,000 cap across all estates claiming this credit statewide.

A shorter filing window than most states

For decedents dying on or after July 1, 2009, the Connecticut estate tax return and payment are due 6 months after death — three months shorter than the 9-month deadline common elsewhere, with a penalty of 10% of the unpaid tax (or $50, whichever is greater) for late filing.

Facing probate in Connecticut?

A local probate attorney can review your estate — many offer a free consultation.

Talk to a Connecticut attorney

For a resident decedent who also owned real or tangible property outside Connecticut, the tax is reduced by the portion attributable to that out-of-state property; the reverse apportionment applies for a nonresident who owned Connecticut property.

Threshold & rates — frequently asked questions

Has Connecticut's rate always been a flat 12%?

No — before 2023, Connecticut used graduated brackets that changed almost every year as the threshold rose from $2,000,000 in 2005 toward alignment with the federal exemption. The flat 12% rate only took effect for deaths on or after January 1, 2023.

How exactly does the $15,000,000 cap interact with the gift tax?

The cap covers combined lifetime Connecticut gift tax and estate tax. Any Connecticut gift tax already paid by the decedent (or, in some cases, the decedent's spouse) for gifts includable in the decedent's estate reduces the $15,000,000 limit, but never below zero.

What is the private investment fund credit?

A reduction equal to half the amount a decedent invested in a qualifying Connecticut private investment fund or fund of funds for at least ten years, capped at $5,000,000 per decedent and $30,000,000 in aggregate across all estates claiming it.

When is the Connecticut estate tax return due?

6 months after the date of death, for decedents dying on or after July 1, 2009 — shorter than the 9-month deadline common in most other states.

This page provides general guidance only and is not legal or tax advice. Based on Conn. Gen. Stat. §12-391, §12-392. Confirm current figures with the Connecticut Department of Revenue Services or a licensed attorney before acting.