Connecticut Inheritance Tax and Estate Tax: What Families Actually Owe

Connecticut does not have a separate inheritance tax — the kind that charges a percentage based on who receives the money. What it does have is a state-level estate tax. And as of 2026, the estate tax exemption has climbed high enough that the overwhelming majority of Connecticut families will owe nothing.

But there's a catch that blindsides nearly every executor: even when an estate owes no tax at all, Connecticut still requires a specific tax return to be filed within six months of the date of death. Missing that deadline costs money even if the underlying tax bill is zero.

This article covers the full 2026 picture: the estate tax threshold, who actually owes it, the mandatory filing requirement that applies to everyone, and the probate fee structure that functions like a separate wealth transfer tax on top of everything else.

Connecticut Has an Estate Tax, Not an Inheritance Tax

First, the distinction matters. An inheritance tax is levied on the person who receives money from an estate, based on their relationship to the deceased — some states charge more for distant relatives or non-relatives. Connecticut does not have this.

A state estate tax is levied on the estate itself, based on its total value, before any distributions happen. Connecticut has this, and it is the only state in the country that imposes both a state-level estate tax and a state-level gift tax.

For decedents who die in 2026 or later, the Connecticut estate tax exemption is permanently aligned with the federal exemption: $15 million per individual, indexed annually for inflation. Estates below that threshold owe no Connecticut estate tax. Given Connecticut's median estate values, this means the vast majority of families — including most homeowners with substantial investment accounts — will not owe any state estate tax.

For estates that do exceed $15 million, the tax rate is a flat 12% on the amount above the exemption.

One important difference from federal estate tax: Connecticut does not allow portability. A surviving spouse cannot inherit their deceased spouse's unused state exemption. This is mainly relevant for very high-net-worth couples doing tax planning, but it's worth knowing.

The CT-706 NT: The Required Filing Even When No Tax Is Owed

This is where Connecticut's system creates genuine hardship for ordinary families.

Even if an estate is worth $400,000 and owes exactly $0 in Connecticut estate tax, the executor is legally required to file the Connecticut Estate Tax Return for Nontaxable Estates (Form CT-706 NT) with the probate court within six months of the date of death.

Why does Connecticut require a tax return when there's no tax? The CT-706 NT is the mechanism by which the probate court calculates and invoices the statutory probate fee — a separate fee that applies to all Connecticut estates based on the total value of the gross estate. Until the CT-706 NT is filed, the court cannot calculate what it's owed, so it holds up the entire process.

The consequences of missing the six-month deadline are automatic and financial. Connecticut charges 0.5% per month interest on the unpaid statutory probate fee starting from the date the return was due, not the date the fee is billed. That penalty begins accruing even if the executor didn't know the filing was required.

Beyond the fee penalty, real estate cannot be sold or transferred until the CT-706 NT is filed and the probate court issues a Certificate Releasing Connecticut Estate Tax Liens (Form PC-256). Connecticut places an invisible, automatic lien on all real property of every deceased resident the moment they die. The lien clears only after the CT-706 NT is reviewed and approved. Families who discover this during a pending home sale — when the title company flags the lien during closing — are often caught completely off guard.

If more time is needed to gather asset values before filing, the executor can request an extension using Form CT-706 NT EXT. This must be submitted to the probate court before the six-month deadline, not after. A timely extension request stops the interest penalty clock.

The Statutory Probate Fee: Connecticut's Hidden Cost

The estate tax question and the probate fee question are separate, and the probate fee catches many families off guard even after they've confirmed they owe no estate tax.

Connecticut calculates its probate fee based on the gross taxable estate — not just assets that pass through probate. Joint bank accounts, living trusts, payable-on-death accounts, life insurance proceeds, and other non-probate assets are all included in the fee base. Families who spent years setting up trusts to "avoid probate" are frequently shocked when they receive the probate court's invoice.

For estates of decedents who died on or after July 1, 2016, the fee schedule is:

• $0 to $500: flat $25
• $501 to $1,000: flat $50
• $1,000 to $10,000: $50, plus 1% of the amount over $1,000
• $10,000 to $500,000: $150, plus 0.35% of the amount over $10,000
• $500,000 to $2,000,000: $1,865, plus 0.25% of the amount over $500,000
• $2,000,000 and over: $5,615, plus 0.50% of the amount over $2,000,000

There is a partial reduction: any portion of the estate that passes to a surviving spouse is assessed at 50% of the normal rate for the fee calculation.

For a straightforward estate worth $800,000 where half passes to a surviving spouse, the math is not trivial and the fee is real money — several thousand dollars at minimum. And since Connecticut removed the maximum cap on probate fees in 2015, high-net-worth estates face open-ended exposure.

The fee is invoiced by the court after the CT-706 NT is reviewed. If the fee is not paid within 30 days of the invoice date, that same 0.5% monthly interest penalty applies to the unpaid balance.

The Final Personal Income Tax Return

In addition to the estate tax return, the executor is responsible for filing a final Connecticut personal income tax return (Form CT-1040) for the decedent, covering the period from January 1 of the year of death through the date of death. The due date is April 15 of the following year — same deadline as a regular personal return.

If the decedent is owed a refund and a surviving spouse is not filing the return, the executor must attach a completed federal Form 1310 (Statement of Person Claiming Refund Due a Deceased Taxpayer) to the Connecticut return to claim the refund.

What Most Connecticut Families Should Expect

For most Connecticut families settling an estate in 2026:

• No Connecticut estate tax will be owed (exemption is $15 million)
• The CT-706 NT must still be filed within six months of death — this is mandatory
• The statutory probate fee will apply to the full gross estate value, including non-probate assets
• Real estate cannot be sold or transferred until the CT-706 NT triggers the release of the state's automatic lien

The filing deadline and the fee structure are where most families run into trouble — not because the law is obscure, but because the state provides the forms without making clear why the nontaxable return is still required or what happens if it's skipped.

If you're working through the probate process and want a step-by-step walkthrough of the CT-706 NT, the fee calculation, and the lien release process for real estate, the Connecticut Estate Settlement Guide covers each stage in the order you need to complete it.

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