On point
FEDERAL RESEARCH
Federal Case Law Search: Search the Federal Case Law Database of Circuit and District Court Opinions in Plain English
Ask a federal question the way you would ask a colleague and get back opinions from the Supreme Court, the thirteen courts of appeals, and the ninety-four district courts, with the citation you file and the holding in plain language.
Last updated July 2026 · US firms · Research tool, not legal advice
CASESEARCH · RESEARCH
Federal + state
|
Try:
Reading opinions
Finding the authorities that answer your question...
Controlling statute
The controlling statute is surfaced alongside the case law so you read the code and the precedents together.
Plain-English answer
Research memo
- Question
- Short answer
- Authorities
Casesearch shows you the sources. Always read the full opinion and verify citations before you rely on them.
The short answer
Federal case law search means finding the decisions of the United States Supreme Court, the 13 federal courts of appeals, and the 94 federal district courts that control a federal question. Weight follows the structure: Supreme Court decisions bind every court in the country, a published circuit opinion binds the district courts inside that circuit and later panels of that same circuit, and a district court opinion binds nobody. The Supreme Court said so directly in Camreta v. Greene, 563 U.S. 692 (2011): a federal district judge's decision "is not binding precedent in either a different judicial district, the same judicial district, or even upon the same judge in a different case." Circuit opinions since 2021 are cited to F.4th, district opinions to F. Supp. 3d.
94
federal judicial districts, at least one in every state
13
courts of appeals: 11 numbered, plus D.C. and Federal
F.4th
the circuit reporter series that began in 2021
$0.10
per PACER page for dockets, though opinions are free
Side by side
The federal court structure and what actually binds your court
Federal precedent is vertical, not horizontal. A court is bound by the courts above it in its own line of appeal and by nothing else, which is why a Ninth Circuit holding is only persuasive in Texas.
| Court | What it decides | How it is cited | Precedential weight |
|---|---|---|---|
| United States Supreme Court | Certiorari review, circuit splits, federal constitutional and statutory questions | U.S., with S. Ct. and L. Ed. 2d parallels | Binding on every federal and state court in the country |
| Courts of appeals (published) | Appeals from the district courts and many agency decisions | F.4th since 2021, F.3d for 1993 to 2021 | Binding inside that circuit, on district courts and later panels |
| Courts of appeals (unpublished) | The same appeals, resolved without a precedential opinion | WL or LEXIS cite, or Fed. Appx. through 2021 | Citable under FRAP 32.1 if issued on or after Jan 1, 2007, but generally not binding |
| District courts | Federal trials, motions, and the bulk of written federal opinions | F. Supp. 3d, or a WL or docket cite if unreported | Binding on no court, persuasive only, per Camreta footnote 7 |
| Bankruptcy and specialty courts | Bankruptcy, tax, veterans, international trade, federal claims | B.R., T.C., Fed. Cl., depending on the court | Binding within their own appellate line only |
| State supreme courts on state law | The meaning of that state's own law, including in diversity cases | The state reporter plus the regional reporter | Binding on federal courts applying that state's law under Erie |
Casesearch is a research accelerator, not legal advice. Confirm the circuit, the publication status, and the current treatment before you file.
How do I search federal case law?
Start by naming your circuit, because in federal practice the circuit decides which authority is mandatory and which is merely interesting. A published Second Circuit opinion controls a case in the Southern District of New York and does nothing at all for a case in the Northern District of Georgia. So the first move is not to search for the best-reasoned opinion in the country; it is to search for the controlling opinion in your line of appeal, then look outward for persuasive support.
Then describe the issue as a full sentence rather than a keyword string. Federal questions turn on statutory text, a rule number, and a procedural posture, so put all three in the query: the statute or rule, what the parties did, and what stage the case is at. "Whether a Rule 12(b)(6) dismissal is proper when the complaint pleads only formulaic recitations of an antitrust conspiracy" gets you further than "12b6 antitrust dismissal" because it tells the search what the case has to be about.
Finally, sort what comes back by weight before you read for quality. Supreme Court first, then published opinions from your own circuit, then other circuits, then district courts. A district court opinion that says exactly what you want is worth quoting only after you have confirmed that no binding authority in your circuit says otherwise, and there is no substitute for checking whether the circuit has spoken.
Name the circuit first
Mandatory authority is whatever binds your court, and that starts with which circuit you are in.
Search in full sentences
Include the statute or rule number, the conduct, and the procedural posture.
Rank by weight, then by reasoning
Supreme Court, then your circuit, then sister circuits, then district courts.
Watch for a circuit split
If sister circuits disagree, say so openly in the brief and argue why your circuit's rule or the better reasoning controls.
Is a federal district court decision binding precedent?
No. A federal district court decision binds the parties in that case and nobody else. The Supreme Court put the point about as plainly as it can be put in footnote 7 of Camreta v. Greene, 563 U.S. 692 (2011), noting that a district judge's decision is not binding precedent in a different district, in the same district, or even on the same judge in a later case. District opinions are persuasive authority, sometimes very persuasive, but they are never mandatory.
This trips up more research than any other federal rule, because district courts write the overwhelming majority of published federal reasoning. F. Supp. 3d is thick with careful, thorough opinions, and a keyword search will hand you dozens of them. If you build a brief on a stack of district court decisions without checking what your circuit has held, you have written a memo about what judges have thought rather than about what the law requires. Find the circuit authority first, then use district opinions to show how that rule has been applied to facts like yours.
The mirror-image rule is the prior panel precedent rule. Once a three-judge panel of a circuit issues a published opinion, later panels of that circuit must follow it; only the en banc court or the Supreme Court can overrule it. That is why a 2009 published panel opinion can still be controlling in a 2026 case even though newer district opinions have questioned it. Date order is not the same as authority order.
How do I cite a federal case?
Federal citation is simpler than state citation because there is one national reporter system. Supreme Court opinions cite to United States Reports, the official reporter, for example Twombly v. Bell Atlantic Corp. as 550 U.S. 544 (2007), with the Supreme Court Reporter (S. Ct.) and Lawyers' Edition (L. Ed. 2d) as parallels. Courts of appeals opinions cite to the Federal Reporter: F.4th for opinions since 2021, F.3d for 1993 through 2021, and F.2d before that, always with the circuit and year in the parenthetical, for example (9th Cir. 2023).
District court opinions cite to the Federal Supplement, currently F. Supp. 3d, with the district and year in the parenthetical, such as (S.D.N.Y. 2022). Bankruptcy opinions go in the Bankruptcy Reporter (B.R.). When an opinion has not made it into a printed reporter yet, you cite the electronic database or the docket: a Westlaw cite in the form 2026 WL 1234567, or the case number, court, and date of the slip opinion.
Unpublished federal appellate opinions used to appear in the Federal Appendix, which West stopped publishing in 2021 after a twenty-year run. Those opinions still exist and are still citable under Federal Rule of Appellate Procedure 32.1 if they were issued on or after January 1, 2007, but you now cite them to Westlaw, Lexis, or the court's own docket. If any of this feels like a foreign alphabet, our guide to reading a legal citation walks through each piece.
Supreme Court
U.S. is the official reporter, with S. Ct. and L. Ed. 2d parallels, for example 550 U.S. 544 (2007).
Courts of appeals
F.4th since 2021, F.3d for 1993 to 2021, with the circuit in the parenthetical.
District courts
F. Supp. 3d, with the district abbreviation and year, such as (E.D. Va. 2024).
Not yet reported
Use the WL or LEXIS cite, or the docket number, court, and decision date.
What is the difference between a federal case and a state case?
Federal courts are courts of limited jurisdiction. They hear a case only if it raises a federal question, if the parties are citizens of different states and more than 75,000 dollars is at stake, or if a specific statute puts the subject in federal court, as bankruptcy and patent law do. State courts, by contrast, are courts of general jurisdiction and can hear almost anything, including most federal claims. That asymmetry is why a plaintiff often gets to choose and a defendant often litigates about removal.
The research consequence is that the two systems produce different kinds of authority for the same dispute. Under Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938), a federal court sitting in diversity applies state substantive law and federal procedural law. So a federal opinion predicting how the Supreme Court of Ohio would rule on an Ohio contract question is persuasive, not binding, in an Ohio state court. Conversely, a state court deciding a federal constitutional question is bound by the United States Supreme Court but not by the circuit that sits over its state.
For a researcher, that means a complete answer usually needs both searches. If your issue is a state-law claim removed to federal court, you are looking for state supreme court authority on the substance and circuit authority on procedure. Our state pages cover the state side, from <a href="/california-case-law-search" class="underline decoration-oxblood-deep/40 underline-offset-2 hover:decoration-oxblood-deep">California</a> and <a href="/texas-case-law-search" class="underline decoration-oxblood-deep/40 underline-offset-2 hover:decoration-oxblood-deep">Texas</a> to <a href="/new-york-case-law-search" class="underline decoration-oxblood-deep/40 underline-offset-2 hover:decoration-oxblood-deep">New York</a>, and this page covers the federal side.
Where can I find federal court opinions online for free?
More federal material is free than most lawyers realize. Every federal court posts its own opinions. The govinfo United States Courts Opinions collection, run by the Government Publishing Office with the Administrative Office of the U.S. Courts, carries authenticated opinions from participating appellate, district, and bankruptcy courts. CourtListener, from the nonprofit Free Law Project, holds millions of opinions with full-text search, and its RECAP archive holds federal filings that other users have already paid to pull. Google Scholar covers the reported opinions with decent search.
PACER is the official docket system, and it is worth being precise about what it is. PACER gives you filings and dockets, not a research database with headnotes or a citator. It charges 10 cents a page, capped at 3 dollars per document, and waives the balance entirely if you accrue 30 dollars or less in a quarter. Written opinions carry no fee at all. The full breakdown is in our guide to <a href="/blog/how-much-does-pacer-cost" class="underline decoration-oxblood-deep/40 underline-offset-2 hover:decoration-oxblood-deep">how much PACER costs</a>.
What none of the free sources give you is a treatment check. They will hand you the opinion; they will not tell you that the Fourth Circuit abrogated it en banc in 2023. That verification layer is the reason firms still pay for research, and it is the part you cannot responsibly skip. A self-serve tool that returns cited holdings with a good-law signal covers the everyday federal research job for a fraction of an enterprise seat, and we compare the whole category in the <a href="/legal-research-software" class="underline decoration-oxblood-deep/40 underline-offset-2 hover:decoration-oxblood-deep">legal research software guide</a>.
govinfo
Authenticated opinions from participating federal appellate, district, and bankruptcy courts.
CourtListener and RECAP
Free Law Project's opinion database plus a growing archive of federal filings.
PACER
Official dockets and filings at 10 cents a page, capped at 3 dollars a document, with opinions free.
What is missing
No citator, no plain-language holding, and no alert when later authority undercuts the case.
Frequently asked
Questions buyers ask about federal case law search
How do I search federal case law?
Name your circuit first, because that determines which authority binds your court, then describe the issue as a full sentence including the statute or rule number, the conduct, and the procedural posture. Rank the results by weight: Supreme Court, then published opinions from your own circuit, then sister circuits, then district courts, and run a treatment check before you cite.
Is a federal district court decision binding precedent?
No. A federal district court decision binds only the parties to that case. In Camreta v. Greene, 563 U.S. 692 (2011), the Supreme Court noted that a district judge's decision is not binding precedent in a different judicial district, in the same district, or even on the same judge in a later case. District opinions are persuasive authority only.
Are circuit court decisions binding on district courts?
Yes, within that circuit. A published court of appeals opinion binds every district court in its circuit and binds later three-judge panels of that same circuit under the prior panel precedent rule, until the en banc court or the Supreme Court overrules it. A published opinion from another circuit is persuasive only.
How do I cite a federal case?
Cite Supreme Court opinions to United States Reports, for example 550 U.S. 544 (2007). Cite courts of appeals opinions to the Federal Reporter, F.4th since 2021 and F.3d for 1993 to 2021, with the circuit and year in the parenthetical. Cite district court opinions to F. Supp. 3d with the district and year, and use a WL or docket cite when an opinion is not yet reported.
Can you cite an unpublished federal opinion?
Yes, if it was issued on or after January 1, 2007. Federal Rule of Appellate Procedure 32.1 bars the courts of appeals from prohibiting citation of unpublished dispositions issued from that date forward. Most circuits still treat them as non-precedential, so cite one for its persuasive reasoning and never as controlling authority.
Where can I find federal court opinions for free?
The govinfo United States Courts Opinions collection, CourtListener from the Free Law Project, and Google Scholar all carry federal opinions at no charge, and each federal court posts its own. PACER covers dockets and filings rather than research, charging 10 cents a page with written opinions free. None of the free sources include a citator.
Keep reading
How much does PACER cost
The 10 cents a page fee schedule, the 30 dollar quarterly waiver, and what is free.
California case law search
Ninth Circuit territory, and how California appellate districts bind.
Texas case law search
The two high courts and the fourteen courts of appeals in the Fifth Circuit.
New York case law search
Why the Supreme Court is the trial court and A.D.3d binds statewide.
Washington case law search
Ninth Circuit territory, and three divisions that do not bind each other.
Massachusetts case law search
First Circuit territory, and one Appeals Court that binds statewide.
How to find federal court opinions
govinfo, CourtListener, PACER, and what each source misses.
What decisions are binding in my state
How binding authority works court by court, state by state.
Published vs unpublished opinions
The rule that decides whether an opinion is authority at all.
How to read a legal citation
Reporters, pinpoints, parentheticals, and subsequent history.
Legal research software
The four kinds of research tool and how to choose between them.
Casesearch is a legal research tool, not legal advice. Always read the full opinion and verify citations before relying on them.
Start now
Search federal case law in plain English
Ask your federal question and read the controlling circuit authority, the holdings, and the treatment signal for yourself. A research tool, not legal advice.