IRS Notices
The 90 Day Letter & Tax Court Petition: Basics (2026)
The short answer: a "90 day letter" is the IRS Notice of Deficiency. It says the IRS has decided you owe more tax. You have 90 days from the date on the letter to file a Tax Court petition and dispute the amount before it becomes final — and this deadline can't be extended.
⏱ Your deadline: exactly 90 days from the date printed on the notice (150 days if the letter is addressed to you outside the United States). This is set by law — the Tax Court cannot give you more time. The notice usually prints the last day to file right on the first page. Mark it and do not let it pass.
What a 90 day letter actually is
A 90 day letter and a Tax Court petition go together. The letter — formally called a Notice of Deficiency — is the IRS telling you, "We've determined you owe this much more, and here's your one chance to challenge it before we make it official." It usually arrives as Letter 3219 or as a CP3219A Notice of Deficiency, and it almost always comes by certified mail.
The IRS sends it after a return doesn't match the income or credits in its records, or after an audit or an unanswered CP2000 notice. By the time the deficiency notice goes out, the earlier "let's fix this" letters have already passed. This is the legal step the IRS must take before it can assess the extra tax.
Read the IRS's own explanation on the Understanding Your CP3219A Notice page. The key point: a 90 day letter is not a bill yet. It's a proposal — and the clock to respond is short and firm.
Why the 90-day deadline matters so much
The deadline is the whole point. Filing a Tax Court petition within 90 days is the only way to dispute the tax without paying it first. That's a big deal. Once you petition, the IRS cannot assess or collect the disputed amount while your case is open.
Count the 90 days from the date on the letter — not the day you opened it. If the last day falls on a Saturday, Sunday, or legal holiday, it rolls to the next business day. There are no other extensions. The Tax Court has dismissed petitions filed even a single day late.
What happens if you ignore it
If 90 days pass with no petition, the IRS assesses the tax it proposed. From there, the automated collection sequence takes over — and it doesn't slow down:
- The tax is assessed — the proposed amount becomes a real, legal debt with penalties and interest.
- CP14 and reminder notices — your first bill, then follow-up notices as the balance grows monthly.
- CP504 — Intent to Levy — the IRS can take your state tax refund and a federal tax lien becomes likely.
- LT11 / Letter 1058 — Final Notice — after 30 days, the IRS can garnish wages and levy bank accounts. You'll have CDP hearing appeal rights here, but you can no longer challenge whether you owe the tax in the same way.
After the 90 days run out, you can still fight the amount — but only by paying it in full first and then filing a refund claim. That's a much harder, slower road. The deadline you're staring at today is your best and cheapest chance to be heard.
Your options when you get a 90 day letter
You don't have to file a petition just because you got the letter. Look at what the notice actually claims, then pick the path that fits:
- You agree with the IRS. Sign and return the enclosed waiver (often Form 5564) and arrange to pay. If you can't pay in full, you can still set up a plan — see the options below.
- You disagree and want to dispute it. File a Tax Court petition within 90 days. This protects your right to argue the amount before you pay.
- The notice is based on missing information. Sometimes the IRS just never got a form, a basis figure, or proof of a deduction. You can send corrected information to the IRS contact on the notice — but if the 90 days are running out, file the petition anyway to protect yourself. You can still settle afterward.
- You can't pay what's owed. Whether you agree now or after Tax Court, you may qualify for an installment agreement, Currently Not Collectible status, penalty relief, or an Offer in Compromise depending on your finances.
How to respond, step by step
- Find the deadline date. The last day to petition is usually printed on page one. Count 90 days from the notice date yourself to confirm it, and write it on your calendar.
- Read what the IRS is changing. Compare the notice line by line with your return. Decide whether you agree, partly agree, or disagree.
- If you agree: sign the waiver, then handle payment. Use IRS.gov/payments or set up a plan if you can't pay in full.
- If you disagree: file your petition with the United States Tax Court before the deadline. You can file online through the court's DAWSON electronic filing system or by mail. The filing fee is $60, with a hardship waiver available.
- Keep proof of everything. Save the envelope, the certified mail date, copies of your petition, and your mailing receipt. Dates win and lose these cases.
- Get a professional review first if the amount is large or you're unsure. The right move depends on your numbers — a quick review can tell you whether to petition, correct the record, or simply arrange payment.
One reassuring fact: most Tax Court cases never reach trial. After you file, the case is usually sent to IRS Appeals, where many disputes are settled. Filing the petition is what gets you that seat at the table.
Staring at a 90 day deadline?
Don't let the clock run out. Send us a photo of your notice and an experienced tax professional will tell you exactly where you stand, what the deadline really is, and whether a Tax Court petition is your best move — free, confidential, no pressure.
90 day letter & Tax Court petition questions, answered
What is a 90 day letter from the IRS?
A 90 day letter is the IRS's Notice of Deficiency — a formal letter (usually Letter 3219 or CP3219A) saying the IRS has determined you owe more tax. It gives you 90 days to either agree and pay or file a petition with the United States Tax Court to dispute the amount before it becomes final.
Can the 90 day deadline to file a Tax Court petition be extended?
No. The 90-day deadline is set by law and the Tax Court cannot extend it. Count exactly 90 days from the date printed on the notice (150 days if the notice is addressed to you outside the United States). If the last day is a weekend or legal holiday, the deadline moves to the next business day. Miss it and you lose the right to dispute the tax without paying it first.
What happens if I ignore the 90 day letter?
If you do nothing within 90 days, the IRS assesses the tax it proposed. After that, it sends a bill, then moves into the automated collection sequence — reminder notices, intent-to-levy notices, liens, and eventually wage garnishments and bank levies. You can still dispute the amount later, but only after paying it and filing a refund claim, which is far harder.
Do I need a lawyer to file a Tax Court petition?
No. You can file and represent yourself, and the Tax Court has a simplified procedure for cases of $50,000 or less per tax year. Many cases settle with IRS Appeals before trial. That said, having an experienced tax professional review your notice first helps you decide whether to petition, request a correction, or simply set up a payment arrangement.
How much does it cost to file a Tax Court petition?
The U.S. Tax Court filing fee is $60, and you can pay it or request a waiver based on financial hardship. You can file electronically through the court's DAWSON system or by mail. Filing a petition does not, by itself, cost you the disputed tax — it pauses assessment while your case is reviewed.
This guide is general information, not tax or legal advice for your specific situation. Eligibility for IRS programs depends on individual facts and circumstances; no outcome is guaranteed. If you're facing a filing deadline, you can also contact the Taxpayer Advocate Service, an independent organization within the IRS.