IRS Notice of Deficiency (90-Day Letter): Your Tax Court Rights

The IRS issues a Notice of Deficiency when:

• You didn't respond to CP2000 - The IRS made changes you didn't contest
• Audit concluded - An examination resulted in proposed changes you didn't agree to
• Substitute for Return (SFR) - The IRS filed a return for you
• Mathematical error correction - In some cases

The Notice of Deficiency is required by law before the IRS can assess additional tax. It's your constitutional protection - your day in court before the government takes your money.

The Notice of Deficiency gives you a unique right:

Petition Tax Court Within 90 Days

File a petition with the United States Tax Court. This:

• Stops the IRS from assessing the tax until the case is resolved
• Gives you a chance to dispute the tax without paying first
• Allows you to present evidence and arguments to a judge

Small Tax Case Procedure

For disputes under $50,000, you can use simplified "S Case" procedures - less formal, no lawyer required.

If You Don't Petition

After 90 days, the IRS assesses the tax and begins collection. Your only recourse then is to pay the full amount and sue for a refund in federal court.

Unlike most IRS deadlines, this one cannot be extended:

• No extensions - The IRS cannot give you more time
• No exceptions - Even Tax Court cannot accept late petitions (with very rare exceptions)
• Mailing date counts - The petition must be postmarked within 90 days
• Calculate carefully - Count from the date on the notice, not when you received it

If you're close to the deadline and undecided, file the petition anyway. You can always settle or concede later, but you can't resurrect a missed deadline.