You Just Got a 90-Day Letter From the IRS. Here's What It Means.

You opened your mailbox and found a certified letter from the IRS. The envelope contains something called a "Notice of Deficiency" or "Statutory Notice of Deficiency." The letter says you have 90 days to respond.

Your heart is racing. You're not sure what this means or what happens if you miss the deadline.

Take a breath. This guide explains exactly what a 90-day letter is, what your options are, and the critical mistakes you need to avoid.

What Is a 90-Day Letter?

A 90-day letter (also called a Notice of Deficiency, Statutory Notice of Deficiency, or your "ticket to Tax Court") is the IRS's formal notice that they believe you owe additional tax. Common versions include CP3219A and CP3219N.

This isn't just another IRS notice. It's a legal document that gives you a specific right: the right to challenge the IRS's decision in US Tax Court without paying the disputed amount first.

That last part is important. If you want to fight the IRS in any other court (District Court or Court of Federal Claims), you must pay the full amount first, then sue for a refund. Tax Court is the only forum where you can dispute first, pay later.

The 90-Day Deadline Is Real

You have exactly 90 days from the date on the notice to file a petition with the US Tax Court. If the notice was sent to an address outside the United States, you have 150 days.

This deadline cannot be extended. Not by the IRS. Not by the Tax Court. Not by anyone. If day 90 falls on a Saturday, Sunday, or legal holiday, you have until the next business day.

If you miss this deadline, the IRS will assess the tax automatically. You lose your right to challenge it in Tax Court. Your only remaining option would be to pay the full amount and file a refund suit in a different court.

Your Three Options

Option 1: Agree with the IRS

If the IRS is correct, sign Form 5564 (included with your notice) and return it. The IRS will assess the tax, and you can set up a payment plan if needed.

Option 2: Try to Resolve It Without Court

You can contact the IRS during the 90-day period to provide additional information or documentation. If the IRS agrees with your position, they may withdraw or modify the notice.

Important: Contacting the IRS does not extend your 90-day deadline. If negotiations fail and you've run out of time, you've lost your Tax Court option.

Option 3: File a Petition with the US Tax Court

If you disagree with the IRS and want to preserve your right to challenge their decision, you must file a petition with the Tax Court before the deadline.

You can file electronically through DAWSON (the Tax Court's online system) or mail a paper petition. The filing fee is $60, though fee waivers are available for those who qualify.

Should You Represent Yourself?

About 85% of Tax Court petitioners represent themselves (called "pro se"). You have the legal right to do this.

However, the statistics are sobering: pro se petitioners prevail in full or in part only about 13% of the time, compared to 23% for represented taxpayers.

Common mistakes pro se petitioners make:

• Missing procedural deadlines after filing
• Failing to communicate with IRS counsel before trial
• Showing up to trial with documents the IRS has never seen
• Not understanding what issues they need to prove

If your case involves less than $50,000 per year, you can elect "small case" procedures, which are less formal. The trade-off: you cannot appeal a small case decision.

Who Can Represent You?

Only two types of professionals can represent you in Tax Court:

1. Attorneys admitted to the Tax Court bar
2. US Tax Court Practitioners (USTCPs) — CPAs or Enrolled Agents who have passed a special exam

Regular CPAs and Enrolled Agents cannot represent you in Tax Court unless they hold the USTCP credential. There are fewer than 300 USTCPs in the entire country.

If you cannot afford representation, Low Income Taxpayer Clinics (LITCs) may be able to help for free if your income is below 250% of the poverty line and your dispute is under $50,000.

What Happens After You File?

• The IRS has 60 days to respond to your petition
• Your case will typically be assigned to IRS Appeals for settlement discussions
• About 95-96% of Tax Court cases settle before trial
• If you don't settle, you'll receive a trial date (usually 5+ months out)
• The first day of trial is called the "calendar call" where the judge reviews pending cases

The Bottom Line

A 90-day letter is serious, but it's not the end of the world. You have options. The most important thing is to understand your deadline and make a deliberate choice before it passes.

Don't ignore the letter. Don't assume someone else will handle it. And don't wait until day 89 to figure out what to do.

This article is for informational purposes only and does not constitute legal or tax advice. Consult a qualified professional for advice on your specific situation.