Think of it like hitting the emergency stop before a machine locks up and crushes your options. A Tax Court petition is the formal paperwork filed to ask the United States Tax Court to review an IRS decision before you pay the disputed tax. Most often, it follows a Notice of Deficiency - the IRS letter that says it plans to assess more tax, penalties, or both. Filing the petition on time puts the fight in front of a judge instead of leaving the IRS to steamroll ahead.

The deadline is brutal and unforgiving. Under Internal Revenue Code §6213(a), you generally get 90 days from the date the Notice of Deficiency is mailed, or 150 days if it was addressed outside the United States. Miss that window and the IRS can assess the tax, and your clean prepayment path to Tax Court is usually gone. Then you may be stuck paying first and suing later in another court.

That matters in real life because tax disputes do not wait for a good time. If someone in Wyoming is already dealing with lost wages, a work injury, or a disputed settlement, an IRS claim can turn into penalties, interest, liens, or levies fast. Wyoming has no state income tax, but federal tax problems still hit hard, whether you work near Cheyenne or on a remote industrial site. A Tax Court petition is how you stop complaining and actually contest the bill.