Short answer: Tax litigation is the process of formally disputing the IRS in court when you cannot resolve a disagreement through an audit or appeal. Most tax litigation happens in the U.S. Tax Court, the only federal court where you can challenge a proposed tax before paying it. After the IRS issues a Notice of Deficiency, you have exactly 90 days to file a petition, and the vast majority of these cases settle before trial. A tax litigation attorney manages that process and protects your deadlines.
Litigation sounds dramatic, but for most taxpayers it is a structured negotiation with a courthouse backstop. Knowing the forum and the deadlines changes the leverage in every conversation with the IRS.
Key takeaways
- Tax litigation resolves disputes the audit and appeals process could not settle.
- The U.S. Tax Court lets you dispute the IRS without paying the tax first.
- A Notice of Deficiency gives you 90 days to petition the Tax Court.
- Most Tax Court cases settle before trial rather than going to a hearing.
Last updated: July 2026
What is tax litigation?
Tax litigation is the formal legal process of contesting the IRS in court after informal options fail. It usually begins when the IRS issues a Notice of Deficiency and the taxpayer files a petition with the U.S. Tax Court within the strict 90-day window the law allows [Source: Taxpayer Advocate Service, taxpayeradvocate.irs.gov]. From there the case follows court procedures, including discovery and settlement conferences.
Litigation is the last stage of a longer path that often starts with an audit. Our guides on what to expect during a tax audit and responding to an IRS notice explain the steps that come before, and the firm’s tax audit and litigation practice covers the full range.
What is the U.S. Tax Court and why does it matter?
The U.S. Tax Court is the only federal court where a taxpayer can dispute an IRS assessment without first paying the amount in question [Source: U.S. Tax Court, ustaxcourt.gov]. Every other forum requires you to pay the tax and then sue for a refund. For a taxpayer facing a large proposed bill, that prepayment difference can be decisive.
Because of this advantage, the Tax Court handles the majority of tax disputes. The ability to litigate without paying first preserves cash and keeps options open, which is why representation admitted to this court adds real value to a case.
What is a Notice of Deficiency, or 90-day letter?
A Notice of Deficiency is the IRS’s formal statement that you owe additional tax, and it is often called the 90-day letter for good reason. You have 90 days from the date on the notice to petition the U.S. Tax Court, and that deadline is jurisdictional, meaning the court cannot hear a late petition [Source: Taxpayer Advocate Service, taxpayeradvocate.irs.gov]. Missing it forecloses your chance to dispute the tax before paying.
This is why the notice should never sit unopened on a desk. Prompt action preserves your rights, a theme that also runs through our overview of IRS audit red flags and the firm’s tax resolution services for balances that become final.
Do most tax cases go to trial?
No. The great majority of Tax Court cases settle before trial, with estimates ranging from about 85% to over 90% resolved through negotiation rather than a hearing [Source: Taxpayer Advocate Service, taxpayeradvocate.irs.gov]. IRS Appeals and IRS counsel both have authority to settle, and many cases resolve once the government evaluates the strength of the taxpayer’s position.
| Stage | What happens |
|---|---|
| Petition filed | Case docketed within 90 days of the Notice of Deficiency |
| Settlement phase | Roughly 85% to 90% of cases settle here |
| Trial | Only a small share of cases reach a judge |
As Nicholas Rosado, a former IRS Office of Chief Counsel attorney at the firm, notes: “Filing a petition is often what finally gets a case in front of someone with authority to settle. The courthouse door is leverage, even when you never walk through it.” His background is on his attorney profile page.
What is the small tax case procedure?
The Tax Court offers a simplified path for smaller disputes. If the amount in dispute is $50,000 or less for any single tax year, you may elect the small tax case, or “S case,” procedure, which uses relaxed rules of evidence and a faster, less formal hearing [Source: U.S. Tax Court, ustaxcourt.gov]. Many taxpayers handle these cases with less expense than a regular case requires.
The tradeoff is finality: a decision in a small tax case cannot be appealed by either side. That makes the choice between the small case and regular procedures an important early decision, and one where a tax attorney can weigh the amount at stake against the value of preserving appeal rights.
Where can you litigate a tax dispute?
Beyond the Tax Court, taxpayers can sue in a U.S. District Court or the Court of Federal Claims, but both require you to pay the disputed tax first and then sue for a refund [Source: U.S. Tax Court, ustaxcourt.gov]. Each forum has different procedures, judges, and strategic advantages, and the right choice depends on the facts of the case.
Choosing the forum is itself a strategic decision that shapes the entire dispute. Because the analysis blends procedure and substance, it is one of the first questions the firm’s litigation team evaluates for clients in San Jose and Walnut Creek.
Why hire a tax litigation attorney with IRS experience?
Only attorneys, CPAs, and enrolled agents have unlimited rights to represent taxpayers before the IRS, and litigating in the U.S. Tax Court requires a separate admission beyond a standard bar license [Source: IRS Topic 254, irs.gov]. Former IRS attorneys bring added insight because they once evaluated cases from the government’s side.
That inside perspective helps anticipate how the IRS will value and resolve a dispute. The firm was founded by former IRS Office of Chief Counsel attorneys, including Anthony Kim, and this experience shapes how it approaches every contested matter.
How a tax attorney can help with tax litigation
A tax litigation attorney can evaluate whether to petition the Tax Court, protect the 90-day deadline, choose the strongest forum, and negotiate a settlement while preparing for trial if needed. Because tax litigation blends deadlines, procedure, and substantive tax law, experienced counsel reduces the risk of a costly misstep.
Kim & Rosado LLP represents individuals and businesses in tax disputes with the IRS and California agencies from offices in San Jose and Walnut Creek. If you received a Notice of Deficiency or face a contested tax matter, you can schedule a consultation promptly.
Frequently asked questions
How long do I have to file a Tax Court petition?
You have 90 days from the date of the Notice of Deficiency to petition the U.S. Tax Court, or 150 days if the notice is addressed to you outside the United States. The deadline is jurisdictional, so the court cannot accept a late petition.
Do I have to pay the tax before going to Tax Court?
No. The U.S. Tax Court is the only federal forum where you can dispute a proposed tax without paying it first. District Court and the Court of Federal Claims require you to pay and then sue for a refund.
Will my tax case go to trial?
Most likely not. The large majority of Tax Court cases, roughly 85% to 90%, settle before trial through negotiation with IRS Appeals or counsel. Filing a petition often creates the leverage needed to reach a resolution.
Do I need an attorney for Tax Court?
You are not required to have one, but tax litigation involves strict deadlines and complex procedure. An attorney admitted to the U.S. Tax Court, especially one with IRS experience, can protect your rights and improve your position.
This article is for informational purposes only and does not constitute legal advice. Every tax situation is unique. Contact a qualified tax attorney at Kim & Rosado LLP for guidance specific to your circumstances.
Kim & Rosado LLP, San JosePhone: 408-290-0280Kim & Rosado LLP, Walnut Creek
Phone: 925-255-1401
