How to read a tax case or IRS ruling: who it binds and how much it weighs
Not every tax decision carries the same weight. We show how to sort court opinions and IRS guidance, which appeals court covers Illinois and what changed in 2024 when courts stopped deferring to agencies.
Prepared by Prem Tax and Accounting Corp. Last reviewed November 6, 2026. Figures as of November 6, 2026.
Not every tax decision carries the same weight. A Supreme Court opinion binds every federal court. A Tax Court memorandum opinion mostly applies settled law to one set of facts. Before you rely on a headline, hang the decision on the right hook: which court, how high, published or not, and where an appeal would go. We call that the Coat-Rack Court Sort. See the rest of our cases and rulings series.
- Check four things: the court, its level, whether the opinion is published and which circuit an appeal would reach.
- Illinois, Indiana and Wisconsin residents generally appeal Tax Court decisions to the Seventh Circuit.
- Since Loper Bright (2024), courts decide for themselves whether a tax regulation fits the statute.
- IRS FAQs are not precedent, but good-faith reliance can support penalty relief.
| Source | Who must follow it | How much weight |
|---|---|---|
| Supreme Court opinion | Every federal court | Highest |
| Court of appeals, published | Courts in that circuit | Binding there only |
| Court of appeals, unpublished or nonprecedential | Nobody beyond the parties | Limited |
| Tax Court regular opinion (T.C.) | The Tax Court, as its own precedent | Strong in the Tax Court |
| Tax Court memorandum opinion | Mostly applies settled law to facts | Case-specific |
| IRS ruling or procedure in the Internal Revenue Bulletin | May be cited as precedent | Less than a regulation |
| Private letter ruling, chief counsel advice, FAQ | Not precedent | Reliance may help with penalties |
An invented example
Priya lives in Aurora, and the Tax Court is hearing her case. A Fifth Circuit opinion supports her view, but the Seventh Circuit has never ruled. Her appeal would go to the Seventh Circuit, so the Tax Court treats the Fifth Circuit opinion as persuasive only. The parties could agree in writing to a different circuit.
The Coat-Rack Court Sort
- Hang each decision on a hook: court, level and date.
- Mark whether the opinion is published or a memorandum.
- Note the circuit your own appeal would reach.
- Look for the word held, then read what the court decided, not the headline.
- Note the status: final, on appeal or still open.
- Ask an adviser whether your facts match.
Common questions
Does a Tax Court memorandum opinion set a rule for everyone?
No. It mostly applies settled law to the facts of one case. Small tax case decisions, available when $50,000 or less a year is in dispute, cannot be appealed and are not precedent.
Can I rely on an IRS FAQ?
An FAQ is not law, and the law controls if they differ. The IRS says good-faith, reasonable reliance on an FAQ can support relief from penalties that turn on reasonable cause.
Did Loper Bright void Treasury regulations?
No. It changed how courts review them. Earlier decisions that upheld a rule under Chevron still stand as precedent.
Which court hears an Illinois resident's appeal?
For a Tax Court case, usually the Seventh Circuit, based on where you live when the petition is filed. Our [recent decisions list](/current-topics/cases/recent-decisions-and-rulings/) notes how circuits differ.
Official sources
- Supreme Court: Loper Bright Enterprises v. Raimondo, opinion
- Eighth Circuit: 3M Company v. Commissioner, opinion
- D.C. Circuit: Lissack v. Commissioner, opinion
- Cornell Law: 26 U.S.C. 7482, review of Tax Court decisions
- Cornell Law: 26 U.S.C. 6110, public inspection of written determinations
- IRS: reliance on guidance published in the Internal Revenue Bulletin and FAQs
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