IRS Form 4490, “Proof of Claim for Internal Revenue Taxes,” is the formal claim the IRS files against a deceased person’s estate to collect unpaid federal taxes through probate. If you’re the executor or administrator and one has landed on your desk, the IRS is telling you the estate owes taxes and wants to be paid from estate assets before anything goes to heirs or other creditors. How you handle it matters personally, not just for the estate: executors who pay other debts or distribute assets before satisfying a federal tax claim can be held liable for the shortfall out of their own funds.
What the Form Is Telling You
A proof of claim is a written statement the IRS files to assert that a deceased taxpayer owed federal taxes at death, or that the estate itself has generated a tax liability. Depending on state probate rules, the IRS files it with the probate court, with the estate administrator, or both.1Internal Revenue Service. Internal Revenue Manual 5.5.4 – Proof of Claim Procedures in Decedent Cases The form arrives with Letter 4653, a cover letter explaining how the government reads federal law against your state’s probate rules.
The claim can list assessed liabilities — taxes already calculated and posted to the IRS’s books — and estimated liabilities. An estimated claim means the IRS hasn’t finished examining a return, or the decedent never filed one, so the exact amount isn’t final. When that happens, the IRS files a preliminary claim to preserve its position before the probate deadline runs, then files an amended claim once the real number is known.1Internal Revenue Service. Internal Revenue Manual 5.5.4 – Proof of Claim Procedures in Decedent Cases
The form has multiple parts. Part two is the acknowledgment copy: either the court date-stamps it and returns it, or you send back an acknowledgment letter. The IRS expects acknowledgment within 21 days and will follow up, sometimes by certified mail, if it doesn’t hear back.1Internal Revenue Service. Internal Revenue Manual 5.5.4 – Proof of Claim Procedures in Decedent Cases
Why the IRS Filed Against This Estate
The IRS files because it believes the decedent owed federal income or estate tax and wants to collect from the estate before assets are distributed. In many cases, the trigger is the administrator’s own notice to creditors, which alerts the IRS that a probate is open.2Internal Revenue Service. Request a Proof of Claim in a Probate Proceeding The underlying liability might be unfiled returns, unpaid balances on returns that were filed, or an audit adjustment completed after death. If the amount is a surprise, that’s not unusual: decedents often don’t disclose tax problems, and the IRS may have adjusted a return after the fact.
Verify the Amounts Before You Do Anything Else
Read the claim carefully and match every tax period and amount against the decedent’s records. Pull the account transcripts from the IRS — you can request them with Form 4506-T and a copy of your letters testamentary — and compare them line by line with what appears on Form 4490. Errors happen, and estimated claims in particular can overstate the true liability.
If your state’s probate rules don’t route acknowledgment through the court automatically, return part two yourself with a short letter confirming receipt, and calendar the 21-day expectation.
Know Your State’s Probate Deadline
State law controls how long you have to act on a creditor’s claim. The windows vary, but most states give the administrator roughly 30 to 90 days to accept, reject, or negotiate a claim once it’s properly presented. Missing that window creates problems with the court and with the IRS both, so confirm the exact period with the probate court or an estate attorney as soon as the form arrives.
Federal Claims Get Paid First
When an estate can’t pay every creditor in full, federal law puts the government’s claims ahead of most other debts. Under 31 U.S.C. § 3713, when a deceased debtor’s estate in the custody of the executor is not sufficient to pay all debts, the government’s claim must be paid first.3Office of the Law Revision Counsel. 31 USC 3713 – Priority of Government Claims This priority rule doesn’t apply in a formal Title 11 bankruptcy, but it applies in ordinary probate.
In practice: if the estate owes $80,000 to the IRS and $50,000 to a credit card issuer, and holds $100,000 in assets, the IRS gets its full $80,000 before the credit card issuer sees a dollar. The ordering is not optional. It’s a federal statute that overrides the first-come-first-served instincts many people bring to estate debts.
The Personal Liability Trap
This is where executors most often get hurt. Under the same statute, a representative of an estate who pays any part of a debt before paying a claim of the government is personally liable for the unpaid government claims, up to the amount paid to other creditors.3Office of the Law Revision Counsel. 31 USC 3713 – Priority of Government Claims The IRS can collect against you personally using the same assessment and collection tools it would use against the original taxpayer.4Office of the Law Revision Counsel. 26 USC 6901 – Transferred Assets
Consider an executor who distributes $200,000 to heirs and pays the decedent’s mortgage and medical bills, then learns the IRS has filed a $150,000 claim. The remaining assets don’t cover it. The IRS can now pursue that executor personally for up to $150,000, not because of any fraud, but because estate funds went out the door before the federal claim was satisfied. The IRS has one year after the fiduciary liability arises, or until the collection statute expires on the underlying tax, whichever is later, to make the assessment.4Office of the Law Revision Counsel. 26 USC 6901 – Transferred Assets
The safe practice is straightforward. Hold back enough estate assets to cover every known or potential IRS claim before distributing anything to beneficiaries. If the claim is estimated and the final number is still open, wait for the amended claim before making distributions.
Interest and Penalties Keep Running
Death doesn’t stop the interest clock. Interest accrues on unpaid federal taxes from the original due date, and the IRS resets its underpayment rate quarterly. For the first quarter of 2026, the rate is 7 percent.5Internal Revenue Service. Revenue Ruling 2025-22 – Determination of Rate of Interest Starting April 1, 2026, it drops to 6 percent for the second quarter.6Internal Revenue Service. Internal Revenue Bulletin 2026-8 Interest compounds daily, so an unpaid claim grows faster than most people expect.
Accuracy-related penalties may also apply if the IRS finds that the decedent’s return understated income or claimed improper deductions through negligence. That penalty is 20 percent of the underpayment attributable to the error.7Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments The estate can avoid it by showing reasonable cause and good faith, such as documented reliance on a competent tax professional.8eCFR. 26 CFR 1.6664-4 – Reasonable Cause and Good Faith
Disputing the Claim
You don’t have to accept the IRS’s number at face value. If the amounts look wrong, or the claim rests on an estimated liability you believe is inflated, you have options.
Start by asking the examiner or collection employee who filed the claim for a detailed breakdown. Compare each period against the filed returns and the account transcripts. Common errors include tax computed on an unfiled return using inflated substitute-for-return figures, and penalties that should have been abated.
If the claim comes out of an examination the IRS completed after the taxpayer’s death and you disagree, the dispute follows the ordinary audit path. The IRS will eventually issue a statutory notice of deficiency, often called a 90-day letter, if you can’t resolve it at the examination level. Once the estate receives that notice, the executor has 90 days (150 days if the notice is addressed outside the United States) to petition the U.S. Tax Court for a redetermination without paying the tax first.9GovInfo. 26 USC 6213 – Restrictions Applicable to Deficiencies That deadline is firm. Miss it, and the IRS can assess and collect the full proposed amount.
You can also work within probate. Every state has a procedure for an administrator to reject or partially allow a creditor’s claim. Rejecting the IRS’s claim through the court forces the IRS into additional steps to enforce it, which can create room to negotiate.
What Ignoring It Costs
Silence doesn’t make the claim go away. The IRS will follow up, sometimes by certified mail, and interest keeps accruing on the balance.
If probate closes and assets go out to beneficiaries without the claim being addressed, the executor is exposed to personal liability under the rules above. The IRS can also pursue the transferees themselves — the people who received estate assets — to recover the unpaid tax. The limitations period for assessing against an initial transferee is one year after the limitations period expires against the original taxpayer.4Office of the Law Revision Counsel. 26 USC 6901 – Transferred Assets Between fiduciary liability, transferee liability, and running interest, treating Form 4490 as optional is the single most common way executors end up owing money they could have paid out of estate funds.