Tax Court Basics

The U.S. Tax Court is a federal court created by Congress under Article I of the Constitution. Its role is narrow but important: it hears disputes between taxpayers and the Internal Revenue Service, most often over income, estate, and gift tax. Its defining feature is that it is a prepayment forum — you can challenge the IRS’s determination without first paying the amount in dispute. (If you instead pay the tax and sue for a refund, that case goes to a U.S. district court or the Court of Federal Claims, not the Tax Court.)

Just as important, the Tax Court is a court of limited jurisdiction: it can hear only the specific kinds of tax disputes Congress has authorized, and only when a particular IRS notice or determination opens the door. A balance the IRS says you owe does not, on its own, give you a Tax Court case — and not every balance due can be handled by the Tax Court at all. Tax you reported on your own return but haven’t paid, or amounts the IRS has already assessed without first issuing a notice of deficiency, generally can’t be contested here; those are addressed through other channels, such as paying the tax and suing for a refund, or the IRS’s collection options (an installment agreement, offer in compromise, or a collection due process hearing).

The Court is based in Washington, D.C., but it is a national court: its judges travel to hear cases in dozens of cities across the country, and every case is decided by a judge — there are no juries in Tax Court. Practice before the Court is governed by the U.S. Tax Court Rules of Practice and Procedure, which you can browse in full, for free, on Docket.tax.

Most Tax Court cases begin with a notice of deficiency — a formal IRS letter proposing additional tax. It’s commonly called the “90-day letter” because of the deadline it starts. The notice names the tax years at issue, the amount the IRS says you owe, and — critically — the last date to petition the Tax Court.

From the date the notice is mailed, you generally have 90 days to file a petition (150 days if the notice is addressed to you outside the United States). This deadline comes from statute (Internal Revenue Code § 6213(a)) and is treated as a hard cutoff: miss it, and you usually lose the chance to be heard in Tax Court on that deficiency. A notice of deficiency is not the only ticket to Tax Court — certain IRS collection and other determinations qualify too — but it is by far the most common.

You start a case by filing a petition with the Court. The petition identifies the notice you’re challenging, the tax years involved, and the specific errors you believe the IRS made. What a petition must contain is set out in the Tax Court Rules (Rule 34) — again, browsable on the free Tax Court Rules page.

There is a $60 filing fee, which the Court can waive if you can’t afford it. Once the petition is accepted, the Court assigns your case a docket number and the case becomes part of the public record. From that point on, the IRS is the respondent and you are the petitioner.

If the total amount in dispute is $50,000 or less for any single tax year, you may elect to have your case handled as a small tax case — often called an “S case.” S cases use simplified, more informal procedures designed to be navigable without a lawyer.

The trade-off: a decision in a small tax case is final — it generally cannot be appealed — and it does not set precedent for other cases. Electing S-case status is optional; you can choose the Court’s regular procedures instead if you’d rather preserve appeal rights.

You do not need a lawyer to bring a Tax Court case. Many petitioners appear pro se — representing themselves — and the Court’s procedures, especially in small tax cases, are built with self-represented taxpayers in mind.

You can also be represented by someone admitted to practice before the Tax Court. That includes attorneys (admitted on application) and non-attorneys, such as certain CPAs and enrolled agents, who pass the Court’s admission examination. Admission to the Tax Court bar is separate from being licensed to practice law generally.

If you can’t afford representation, a Low Income Taxpayer Clinic (LITC) may be able to help — for free or a nominal fee. LITCs represent lower-income taxpayers in disputes with the IRS, including audits, appeals, collection matters, and cases in the Tax Court, and they help taxpayers who speak English as a second language understand their rights. Clinics are run by law-school programs, legal-aid organizations, and other nonprofits, and are independent of the IRS (though the IRS partly funds the program under Internal Revenue Code § 7526).

Eligibility is generally based on income — clinics serve taxpayers whose income falls below a set limit — and the amount in dispute usually has to be relatively modest. You can find a clinic in the IRS’s directory (Publication 4134) or through the Taxpayer Advocate Service, and at many Tax Court calendar calls LITC volunteers are on hand to help unrepresented petitioners on the spot.

When a case is decided, the ruling can take several forms — and they carry very different weight as authority:

• Regular (“T.C.”) opinions — issued in cases raising a significant or first-impression legal issue. These are the Court’s most authoritative opinions and are cited as “T.C.” (for example, 160 T.C. No. 5).
• Memorandum opinions (“T.C. Memo.”) — apply already-settled law to the particular facts of a case. They’re citable, but carry less precedential weight than regular opinions.
• Summary opinions (“T.C. Summ. Op.”) — issued in small tax cases. They resolve the parties’ dispute but cannot be cited as precedent.
• Bench opinions — delivered orally by the judge from the bench, usually in straightforward cases, and later transcribed.
• Orders — procedural rulings that manage a case (setting deadlines, granting or denying motions, scheduling). Orders aren’t opinions and generally aren’t precedent, but they can be highly consequential.

Docket.tax maintains searchable archives of both opinions and orders, with AI-generated plain-language summaries.

The Tax Court hears cases in trial sessions held in cities around the country. Weeks before a session, the Court issues a calendar listing the cases set for that place and date, along with a Standing Pretrial Order telling the parties how to prepare.

A session opens with a calendar call, where the judge takes stock of every case on the calendar — which are settled, which need trial, and which need more time. A large share of Tax Court cases settle before trial, and the calendar call is often where that becomes official.

The Tax Court has 19 presidentially appointed judges, each serving a 15-year term, led by a Chief Judge elected by the other judges. Retired judges often keep hearing cases as senior judges, and special trial judges handle small tax cases and certain other matters.

Because a single judge — not a jury — decides each case, knowing who is assigned, and how that judge has approached similar issues, can be genuinely useful. Docket.tax’s judge and counsel search is built around exactly that.

Since 2020, the Court’s official case records live in DAWSON, its public online case-management system. Anyone can search DAWSON for a case and read the public docket — the chronological list of everything filed.

Every case gets a docket number that looks like 12345-23: a sequential number, then the two-digit year the petition was filed. A letter suffix flags a special track — for example, “S” marks a small tax case (12345-23S) and “L” a lien-or-levy collection case. Docket.tax reads these public dockets continuously, so you can track a case and get an alert the moment something new is filed — without refreshing DAWSON yourself.

Petitioner

The taxpayer who files a case in the Tax Court.

Respondent

The Commissioner of Internal Revenue (the IRS) — always the opposing party in a Tax Court case.

Notice of deficiency

The IRS letter proposing additional tax that gives a taxpayer the right — and 90 days — to petition the Tax Court. Also called the 90-day letter.

Deficiency

The additional tax the IRS says is owed, over and above what the taxpayer reported.

Petition

The document that starts a Tax Court case and states what the taxpayer believes the IRS got wrong.

Docket number

A case’s unique identifier, such as 12345-23 (a sequence number and the two-digit filing year); an “S” or “L” suffix marks a special case track.

DAWSON

The Tax Court’s public online case-management and docket-search system, in use since 2020.

Small tax case (S case)

A case with $50,000 or less at stake per year, handled under simplified procedures; its decision cannot be appealed and is not precedent.

Pro se

Representing yourself in a case, without a lawyer.

Low Income Taxpayer Clinic (LITC)

A clinic that represents lower-income taxpayers in IRS disputes — including Tax Court cases — for free or a nominal fee; independent of the IRS.

Stipulation

Facts or documents the parties agree to in writing before trial, so they need not be separately proven.

Calendar call

The opening of a trial session, where the judge checks the status of each case set for that place and date.

Regular (T.C.) opinion

A precedential Tax Court opinion issued in a legally significant or first-impression case.

Memorandum (T.C. Memo.) opinion

An opinion applying settled law to the facts of a case; citable, but less weighty than a regular opinion.

Summary opinion

A decision in a small tax case; it resolves the dispute but cannot be cited as precedent.

Order

A procedural ruling that manages a case (deadlines, motions, scheduling) rather than deciding the merits.

Standing Pretrial Order

The Court’s instructions telling the parties how to prepare for an upcoming trial session.