Letter 3219: The Notice of Deficiency After a Mail Audit

By Forrest Baumhover, CFP®, EA · Last verified September 29, 2026

Letter 3219 is the Statutory Notice of Deficiency the IRS sends when an audit by mail ends without your agreement. It gives you 90 days from the mailing date (150 if the notice is addressed outside the United States) to petition the U.S. Tax Court, and the IRS cannot extend that time.

A missed deadline forfeits: the right under IRC §6213(a) to petition the U.S. Tax Court without paying the deficiency first. After 90 days from the mailing date (150 days if the notice is addressed outside the United States), the IRS assesses the tax, and the remaining court path is to pay in full and sue for a refund

If you got this letter

Got a Letter 3219 in the Mail?

You usually get this letter because the IRS audited your return by mail, proposed changes that raise your tax, and did not get your signed agreement. Letter 3219 is the formal notice that the IRS intends to assess that tax. It is not a bill yet.

The letter starts a 90-day clock (150 days if it was addressed to you outside the United States). The clock runs from the date the IRS mailed it, not the day you opened it. The letter prints the last day you can file a petition with the U.S. Tax Court. Use that date.

Writing to the IRS does not stop the clock. If you disagree and want a judge to hear your case without paying first, you must file a petition with the Tax Court itself, not the IRS, by that last day. If you agree, sign and return Form 5564, which came with the letter.

Get help early. A tax professional, or a Low Income Taxpayer Clinic if you qualify, can read the audit report with you and get the petition filed in time.

What the notice actually says

Letter 3219 is a Notice of Deficiency: the IRS has examined your return, determined that you owe more tax, and states that it intends to assess it. The Taxpayer Advocate Service describes it as the letter "generally" sent "to a taxpayer whose audit was conducted by mail." It encloses the examination report, an explanation of each adjustment on Form 886-A, and Form 5564, Notice of Deficiency - Waiver, for a taxpayer who agrees.

TAS notes that the notice sometimes lists penalties along with the tax but does not include interest. The IRS bills the tax, interest, and any penalties later, once it assesses them. For a joint return, the IRS mails a duplicate Letter 3219 to each spouse separately, even at the same address (IRM 4.19.13.14.1).

Letter 3219 is one of several numbers for the same statutory notice. Letter 531 is the version a field (in-person) audit usually produces, Letter 3219-B the version for a corporation, estate, or trust after a business underreporter review, and CP3219A the version after an unresolved CP2000. (See the IRS Notice Library for the rest.)

What actually triggered it

IRC §6212(a) authorizes the IRS to send a notice of deficiency by certified or registered mail, and IRC §6213(a) bars it from assessing the deficiency until it has sent one and the petition period has run.

In a correspondence audit, the letter comes at a fixed point. IRM 4.19.13.13 sets the sequence: an initial contact letter, then Letter 525, the 30-day letter with the proposed examination report, then, if that goes unanswered, Letter 3219. The IRS also issues it when you answer but do not sign an agreement. So a Letter 3219 usually means an earlier letter went unanswered or unresolved. Reconstruct that history.

Pull the account transcript early. It shows what posted and what correspondence the IRS logged, which helps you rebuild the case file.

Response deadline and what happens if you miss it

IRC §6213(a) sets the period: "Within 90 days, or 150 days if the notice is addressed to a person outside the United States, after the notice of deficiency ... is mailed ... the taxpayer may file a petition with the Tax Court." The clock runs from the mailing date. If the last day falls on a Saturday, a Sunday, or a legal holiday in the District of Columbia, the statute moves it to the next day that is none of those. The IRS reads the 150-day rule a little more broadly than the statute's words: its manual allows 150 days when the taxpayer is outside the United States on the mailing date or the notice goes to an address outside the United States (IRM 4.8.9.11.2). If you were abroad but the letter prints a 90-day date, file by the printed date rather than count on 150.

Treat the last date printed on the letter as your deadline. The final sentence of §6213(a) makes a petition filed on or before "the last date specified for filing such petition by the Secretary in the notice of deficiency" timely. For example, a Letter 3219 mailed on Monday, July 6, 2026 reaches day 90 on Sunday, October 4, 2026, so the last day to petition is Monday, October 5, 2026.

TAS calls the period "the time period prescribed by law" that "cannot be extended by the IRS." Writing to the IRS, calling, or asking the Taxpayer Advocate Service for help does not extend it either.

If the period ends with no petition, the IRS assesses the tax with penalties and interest, and the balance moves into collection, starting with a balance-due notice such as CP14. Two paths remain. You can pay in full and sue for a refund, or, if you have information the IRS never considered, ask for audit reconsideration; the Appeal Channel Router covers when that route fits.

The practitioner's actual next step

Compute the last day from the mailing date, compare it with the date printed on the letter, and calendar the earlier of the two. Then read the audit report line by line and mark each adjustment the client disputes.

If the client agrees, have the client sign Form 5564 and return it; payment can go in now or wait for the bill. If the client cannot pay in full, an installment agreement is the usual next step, and the penalties in the notice may qualify for relief.

If the client disagrees, file a petition with the U.S. Tax Court, not the IRS, before the last day. The Court publishes its petition form and filing guidance on its petitioner page and encourages electronic filing. The Court charges a filing fee and accepts an application to waive it. A client can file on their own. Anyone who files for them must be admitted to practice before the Tax Court; the Court admits attorneys, and nonattorneys only after they pass its examination.

You can still send the IRS documents while the clock runs. The IRS may resolve the case without a trial, but that correspondence does not extend the deadline. Do both: send the documents and file the petition.

A notice of deficiency stops the IRS's clock to assess the new tax. It does not stop the collection clock on tax already assessed; the CSED Calculator explains the difference.

What Letter 3219 gets confused with — and why the distinction matters

The costly confusion is with Letter 525, the 30-day letter that comes before it. Letter 525 proposes the audit changes and asks for a response; Letter 3219 determines the deficiency and starts the Tax Court clock. A reader who answers Letter 3219 the way they would answer Letter 525, by writing back and waiting, can lose the right to go to the Tax Court.

The second confusion is with CP3219A. Both are notices of deficiency with the same 90-day rule, but CP3219A follows an Automated Underreporter case (a CP2000 mismatch), while Letter 3219 usually follows an examination. The case file you rebuild differs: third-party income records for CP3219A, the examiner's report for Letter 3219.

The third is with Letter 531. A field audit usually ends in Letter 531 rather than Letter 3219, and the campus audit unit usually sends Letter 531 instead of Letter 3219 to a taxpayer in bankruptcy, with Notice 1421 explaining how the bankruptcy affects the petition right (IRM 4.19.13.22.1). The waiver form differs.

Common Questions

How long do I have to respond to a Letter 3219?

90 days from the date the IRS mailed it, or 150 days if the notice is addressed to you outside the United States. The letter prints the last day; a petition filed by that date is timely. The IRS cannot extend it.

Does writing to the IRS stop the 90-day clock?

No. The IRS may consider what you send, but only a petition filed with the U.S. Tax Court protects your right to have the case heard without paying first.

What if I agree with the changes?

Sign and return Form 5564, Notice of Deficiency - Waiver, which came with the letter. You can pay now or wait for the IRS bill, which will add interest.