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Connecticut vs Federal Estate Tax: What's Different

The exemption is now identical to the federal one — the rate, the gift tax, and the filing deadline are where the two systems still genuinely diverge.

Conn. Gen. Stat. §12-391(c)(4), (g)(9)

By the FigureMyTax Editorial Team · Reviewed 2026 · How we calculate

Quick answer: the two exemptions now match exactly, but the RATE doesn't — Connecticut's flat 12% can actually be lower than the federal 40% top rate for very large estates. Run your own numbers in the Connecticut estate tax calculator.

One number, defined to move together

Confirmed current: Connecticut defines "federal basic exclusion amount" as "the dollar amount published annually by the Internal Revenue Service at which a decedent would be required to file a federal estate tax return", and the 2023-forward rate schedule taxes only the excess above that same figure. This means Connecticut's threshold rises automatically with the federal one, with no separate state legislative action required.

Same exemption, very different rate

Once an estate exceeds the shared exemption, the two systems diverge sharply. The federal estate tax climbs to a 40% top rate on the largest estates, while Connecticut applies a flat 12% to every dollar above the exemption — meaning a very large estate can genuinely owe less to Connecticut than it owes the IRS on a proportional basis.

The gift tax is where Connecticut stands alone

The federal system taxes large lifetime gifts too, sharing a unified exemption with the federal estate tax. But almost every other state has no gift tax of its own at all. Connecticut is the sole exception, running its own gift tax on the same exemption, rate, and $15,000,000 combined cap as its estate tax.

A shorter deadline, regardless of the shared exemption

Even though the two thresholds now align, the filing deadlines don't: Connecticut requires payment within 6 months of death, while the federal Form 706 isn't due for 9 months — an estate large enough to owe both taxes needs to move faster on the state side.

Facing probate in Connecticut?

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

Talk to a Connecticut attorney

See the full threshold and rate breakdown for exactly how the 12% rate and the $15,000,000 cap work together.

State vs federal — frequently asked questions

Does Connecticut's exemption really equal the federal one now?

Yes — for deaths on or after January 1, 2023, Connecticut's exemption is defined as the federal basic exclusion amount itself, so it rises automatically whenever the IRS adjusts the federal figure, without Connecticut needing to pass new legislation.

If the exemptions match, is the estate tax bill the same?

No — the rates differ sharply. Federal estate tax reaches a 40% top rate on the largest estates, while Connecticut applies a flat 12% to every dollar above the exemption, so a very large estate can owe far more federally than it owes Connecticut.

Does the federal estate tax have anything like Connecticut's gift tax?

The federal system also taxes large lifetime gifts, but nearly every other state has no separate state-level gift tax at all. Connecticut is unique in maintaining its own gift tax alongside its estate tax, sharing the same exemption, rate, and $15,000,000 combined cap.

Could the two exemptions diverge again in the future?

Yes — Connecticut's exemption is tied to current federal law by statute, but future legislation in either Hartford or Washington could change either figure independently, re-creating a gap between them.

Can I owe Connecticut estate tax even if I owe no federal estate tax?

The two exemptions now match exactly, but the RATE doesn't — Connecticut's flat 12% can actually be lower than the federal 40% top rate for very large estates.

Keep going

Connecticut Estate Tax CalculatorYour estimate, based on your answers Connecticut Estate Tax: Threshold & RatesThe flat-rate formula and the $15M cap, explained Connecticut Estate Tax PortabilityWhy there isn't any, and the state-only QTIP instead Connecticut Executor Fee CalculatorWhat the executor gets paid

This page provides general guidance only and is not legal or tax advice. Based on Conn. Gen. Stat. §12-391 and IRS estate and gift tax guidance for 2026. Confirm current figures with the Connecticut Department of Revenue Services, the IRS, or a licensed attorney before acting.