Federal Rule of Appellate Procedure 29 sets out the rules for filing an amicus curiae brief in a federal court of appeals: who may file without asking, how everyone else obtains authorization, what the brief has to contain and disclose, how long it can be, and when it must reach the court. The core deadline is short — seven days after the supported party’s principal brief — and briefs that miss any of the rule’s requirements are frequently rejected.
Who Can File Without Asking
The United States, its officers and agencies, and state governments may file an amicus brief in a court of appeals without seeking anyone’s permission.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae Every other prospective amicus — private organizations, companies, trade associations, individuals — must have authorization before filing. There are two ways to get it.
Consent of All Parties
If every party to the appeal consents, that is enough. The consent does not have to be written. The amicus simply states in the brief that all parties have consented.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae Even a consented-to brief can be struck, though, if it would force a judge on the panel to recuse.
Motion for Leave
When any party refuses consent, the amicus must file a motion for leave of court. The motion has to accompany the proposed brief; you cannot file the motion, wait for a ruling, and then submit the brief. The motion must state the amicus’s interest in the case and explain why the brief is desirable — in other words, why it will help the court decide the appeal rather than duplicating what a party has already argued.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae
What the Brief Must Contain
FRAP 29 and FRAP 32 together set the required contents. Beyond the argument itself, an amicus brief must include:
- A statement of the amicus’s identity, interest in the case, and source of authority to file (consent, government status, or court leave).
- A table of contents with page references.
- A table of authorities listing cases alphabetically, along with statutes and other authorities, with page references.
- A corporate disclosure statement, if the amicus is a nongovernmental corporation, identifying any parent corporation and any publicly held company owning 10% or more of its stock.2Legal Information Institute. Federal Rules of Appellate Procedure Rule 26.1 – Corporate Disclosure Statement
- Cover information identifying the party the amicus supports and stating whether the brief argues for affirmance or reversal, or that the amicus supports neither party.
The Funding and Authorship Disclosure
Unless the amicus is a government entity, the brief must include a three-part disclosure stating whether a party’s counsel authored the brief in whole or in part; whether a party or a party’s counsel contributed money to fund the brief’s preparation or submission; and whether any other person — someone other than the amicus, its members, or its counsel — contributed money for that purpose, and if so, that person’s name.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae The third element is the one filers most often miss. The purpose is transparency: the court wants to know whether a brief presented as an independent perspective is actually funded or written by one of the parties.
Length and Formatting
An amicus brief may be no more than half the maximum length allowed for a party’s principal brief.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae Because a principal brief cannot exceed 13,000 words, 30 pages without a type-volume certification, or 1,300 lines of monospaced type, the amicus ceilings are 6,500 words, 15 pages, or 650 lines.3Legal Information Institute. Federal Rules of Appellate Procedure Rule 32 – Form of Briefs, Appendices, and Other Papers If the court grants a party permission to file a longer brief, that extension does not raise the amicus cap. The amicus limit is fixed to the standard maximum.
The format rules in FRAP 32 apply: 8½-by-11-inch paper, double-spaced text (single-spacing allowed for block quotations, headings, and footnotes), one-inch margins, and a proportionally spaced serif font of at least 14 points, or a monospaced font of no more than 10½ characters per inch. The brief must be bound to lie flat when open, and the cover must be green.3Legal Information Institute. Federal Rules of Appellate Procedure Rule 32 – Form of Briefs, Appendices, and Other Papers
When the brief relies on a type-volume limit rather than the page limit, it must include a certificate of compliance stating the exact word or line count. The filer can rely on the count from the word-processing software.3Legal Information Institute. Federal Rules of Appellate Procedure Rule 32 – Form of Briefs, Appendices, and Other Papers
The Seven-Day Filing Deadline
An amicus brief must be filed no later than seven days after the principal brief of the party it supports. If the amicus supports neither side, the deadline is seven days after the appellant’s or petitioner’s principal brief.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae Any motion for leave must be filed with the brief, not before it.
Seven days is not much time. In practice, most drafting happens before the supported party files, because waiting until the principal brief appears leaves almost nothing for finalizing. The court may grant leave for a later filing on good cause, and may then set a deadline for any response.
Service on the Parties
Under FRAP 25, the amicus must serve a copy of the brief on all parties at or before filing. Service on a represented party goes through counsel. Filing through the court’s electronic filing system counts as service on all registered users. If the brief is not served electronically through the court’s system, it must include a proof of service stating the date, method, and recipients.4Legal Information Institute. Federal Rules of Appellate Procedure Rule 25 – Filing and Service
Different Rules at the Rehearing Stage
FRAP 29(b) governs amicus briefs filed while the court considers whether to grant panel rehearing or rehearing en banc, and the rules there are stricter. The consent path disappears: unless the amicus is a government entity, it must obtain leave of court.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae The word cap is also lower: a rehearing-stage amicus brief may not exceed 2,600 words.5United States Court of Appeals for the Fourth Circuit. Rule 29 Brief of an Amicus Curiae Deadlines split by position:
- Supporting the petition, or supporting neither party: no later than seven days after the petition for rehearing is filed.
- Opposing the petition: no later than the date the court sets for the response.
Oral Argument and Reply Briefs
An amicus may participate in oral argument only with the court’s permission.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae Courts grant that request rarely, typically only where the amicus has expertise the parties cannot supply. Filing a brief does not carry any expectation of argument time.
An amicus may not file a reply brief unless the court specifically permits it.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae
Check the Local Circuit Rules
Each federal circuit can add requirements on top of FRAP 29. Some circuits demand broader disclosure than the national rule — for instance, the Ninth Circuit extends corporate disclosure to associations, joint ventures, partnerships, and limited liability companies appearing as amici, not only corporations.6United States Court of Appeals for the Ninth Circuit. Circuit Rule 26.1-1 Disclosure Statement Others impose their own electronic filing protocols, cover requirements, or tighter page limits. A brief that satisfies FRAP 29 to the letter can still be rejected for violating a local rule, so read the circuit’s rules before you start drafting.