Are You Responsible for an AI Brief You Did Not Write?

The Short Answer

Yes, if your name is on it. The certification that a paper's legal contentions are warranted by existing law attaches to the lawyer who signs or presents the paper, not to the lawyer who wrote it. Courts have now fined local counsel and pro hac vice sponsors who never drafted the brief, never used an AI tool, and in some cases never saw the filing before it went in.

In federal court, Rule 11(b) provides that an attorney who presents a paper to the court, “whether by signing, filing, submitting, or later advocating it,” certifies that its legal contentions are “warranted by existing law.” The Supreme Court has called that responsibility personal and nondelegable: the signer “cannot leave it to some trusted subordinate, or to one of his partners, to satisfy himself that the filed paper is factually and legally responsible.” Pavelic & LeFlore v. Marvel Entertainment Group, 493 U.S. 120, 125 (1989). Pavelic was decided under the pre-1993 rule, and its holding that a law firm could not be sanctioned was superseded in 1993, but its nondelegability principle carries forward. The 1993 Advisory Committee Note to Rule 11 says the same thing in so many words: the person signing, filing, submitting, or advocating a document “has a nondelegable responsibility to the court.”

In New York state court, 22 NYCRR 130-1.1a(b) provides that “by signing a paper, an attorney or party certifies” that the paper is not frivolous, “to the best of that person's knowledge, information and belief, formed after an inquiry reasonable under the circumstances.” And an out-of-state attorney admitted pro hac vice to participate in pre-trial or trial proceedings must be associated with a New York attorney “who shall be the attorney of record in the matter.” 22 NYCRR 520.11(c). In state court, the New York sponsor is on the hook by design.

The Cases Against Local Counsel and Co-Signers

Wadsworth v. Walmart Inc., No. 2:23-CV-118-KHR, ECF No. 181 (D. Wyo. Feb. 24, 2025)

The leading case on local counsel and AI. An associate admitted pro hac vice drafted motions in limine using his firm's in-house AI tool, and eight of the nine cases cited did not exist. Two other lawyers had their electronic signatures on the motions: the supervising partner and local counsel, who had also sponsored the pro hac vice admissions. Neither drafted the motions or reviewed them before filing. The court held that “Mr. Morgan's and Ms. Goody's failure to review the Motions in Limine prior to filing is inconsequential,” found that each violated Rule 11(b)(2), and fined each $1,000. As to local counsel, the court held that she “had a nondelegable duty to ensure a motion or filing is supported by existing law.” The drafting associate was fined $3,000 and his pro hac vice admission was revoked. The court's instruction to every co-signer was short: “If an attorney does not do so, then they should not sign the document.”

Wilder v. President & Fellows of Harvard College (Mass. Super. Ct. June 10, 2026)

The consequence that follows a co-signer into the next case. A Massachusetts trial court denied the Wadsworth supervising partner's application for pro hac vice admission, relying in part on the Wyoming sanction and on his failure to show that he had changed his practice to comply with “his obligation to review any papers filed in court over his signature.” On June 10, 2026, the court refused to vacate the denial, finding that his explanations described “a continuing pattern of inexcusable inattention.” A Rule 11 finding for signing an AI brief is now part of the record a court reviews when you ask to be admitted somewhere else.

Versant Funding LLC v. Teras Breakbulk Ocean Navigation Enterprises, LLC, No. 17-cv-81140, ECF No. 384 (S.D. Fla. May 20, 2025)

Pro hac vice counsel used an AI tool to draft a response that cited a fabricated Delaware decision. Local counsel did not draft the response and did not check the citations, but he signed and filed it. The court found him “certainly less culpable” than the drafter and sanctioned him anyway: a $500 fine, joint liability for the opposing party's fees, and a continuing legal education requirement on AI. Its warning was addressed to the bar at large: “This should be a warning to attorneys who take on the role of local counsel in our federal courts. It is a serious role, and it must be taken seriously by counsel.” Part of the reasoning rests on a Southern District of Florida local rule that requires local counsel to file and serve every paper in the case. The Southern and Eastern Districts of New York have no equivalent local rule, but Rule 11 applies in every district.

Mata v. Avianca, Inc., 678 F. Supp. 3d 443 (S.D.N.Y. 2023)

Usually read as a case about the lawyer who used ChatGPT, Mata is also a case about the lawyer who signed. The attorney who researched and wrote the opposition was not admitted in the Southern District. His colleague was the attorney of record, signed and filed the affirmation, reviewed it only for style, and did not read any of the authority it cited. Judge P. Kevin Castel found that the attorney of record “violated Rule 11 in not reading a single case cited in his March 1 Affirmation in Opposition” and imposed the $5,000 penalty on both lawyers and their firm, jointly and severally. That arrangement, a New York lawyer signing for a lawyer who is not admitted in the court, mirrors the pro hac vice arrangement.

Long v. Quantex Resources, Inc., 108 F.R.D. 416 (S.D.N.Y. 1985), aff'd, 888 F.2d 1376 (2d Cir. 1989) (table)

The duty predates AI by four decades. Local counsel in the Southern District signed motion papers prepared by out-of-state counsel and was sanctioned under Rule 11. The court's reasoning is the clearest statement of the rule in this district: “Federal Rule 11 does not distinguish between foreign and local attorneys, and some attorney has to be accountable to the Court for the contents of papers filed on behalf of a client. It therefore seems to me that at the very least, a local counsel that signs the papers of foreign counsel must read the papers.” Id. at 417. Long was decided under the pre-1993 version of Rule 11, but its core point has not changed.

Williams v. The Estates LLC, No. 1:19-CV-1076 (M.D.N.C. Mar. 23, 2023)

Not an AI case, and a useful one for that reason. Sponsoring local counsel allowed pro hac vice counsel to add his signature to a motion while he was on vacation and did not review it. The court found that he violated Rule 11(b)(2) and (3) and fined him $2,500. The decision also relied on a Middle District of North Carolina local rule requiring local counsel to review and sign all pleadings.

Where the Courts Have Drawn the Line

Not every name in a signature block draws a sanction. The decisions turn on what the lawyer actually did, whether the lawyer's signature was used with permission, and how the sanction issue reached the court.

Johnson v. Dunn, No. 2:21-cv-1701-AMM, ECF No. 204 (N.D. Ala. July 23, 2025)

A partner at a large firm added ChatGPT-generated citations to two motions. The lawyer who signed and filed them without checking the additions, the partner who generated them, and the practice group leader who let his name go into the signature block without checking the citations were publicly reprimanded, disqualified from the case, and referred to their licensing authorities. The court held that the practice group leader “bears responsibility for the false statements of law made to the court over his name in the signature block” even though he “did not personally use AI to generate citations and did not personally file the motions.” Two other lawyers named in the signature block were released, because they had not drafted, revised, or reviewed the motions, had no supervisory role, and had not delegated the use of their signatures. The motions were discovery motions, which Rule 11(d) excludes from Rule 11, so the court acted under its inherent authority.

United States v. Cohen, No. 18-CR-602 (JMF), ECF No. 108 (S.D.N.Y. Mar. 20, 2024)

The Second Circuit counterpoint. Counsel put cases generated by Google Bard into a motion, believing they had come from co-counsel, and did not review them. Judge Jesse M. Furman declined to impose sanctions. Because the sanction issue was raised by the court on its own initiative, Second Circuit law required subjective bad faith, and the conduct, while “embarrassing and certainly negligent, perhaps even grossly negligent,” did not reach that standard. The court still made the duty plain: “it was plainly his responsibility to review the citations before putting them in a submission to the Court.”

Ramirez v. Humala, No. 24-CV-242 (RPK)(JAM) (E.D.N.Y. May 13, 2025)

The limit on Cohen. A paralegal generated the citations with AI tools and the attorney signed the letter without checking them. Judge Rachel P. Kovner imposed a $1,000 sanction under Rule 11, jointly with the firm, and inferred bad faith from the attorney's “failure to make any inquiry at all into the veracity of the cases provided by her paralegal.” In the Second Circuit, a signer who reads nothing may not get the benefit of the bad faith standard.

Woodward Harbor L.L.C. v. City of Mandeville, No. 23-5824 (E.D. La. Mar. 5, 2026)

Three co-signers from two firms relied on the lawyer who drafted the brief. The drafter was fined $1,000. The co-signers were admonished rather than sanctioned, with a reminder that “when delegating brief-drafting responsibility to a cocounsel, the attorneys must still comply with Rule 11 when they act as cosigners to the brief.”

New York State Courts

New York's appellate courts have begun sanctioning AI-fabricated citations under 22 NYCRR Part 130, and their reasoning reaches any lawyer whose name is on the paper.

Deutsche Bank National Trust Co. v. LeTennier, 251 A.D.3d 97, 2026 NY Slip Op 00040 (3d Dept 2026)

The Third Department sanctioned counsel $5,000 under 22 NYCRR 130-1.1 for papers containing fabricated authority, and addressed delegation directly: “As with the work from a paralegal, intern or another attorney, the use of GenAI in no way abrogates an attorney's or litigant's obligation to fact check and cite check every document filed with a court.”

Landberg v. City of New York, 2026 NY Slip Op 03935 (2d Dept June 23, 2026)

The Second Department sanctioned the drafting attorney $8,000 and then sanctioned the law firm $2,500 separately, even though it credited that the attorney had violated firm policy: “as the law firm's name appeared on a brief that contained significant misrepresentations, and in light of the deterrent purpose of sanctions, we deem it appropriate to impose a monetary sanction on the law firm.” The firm's name on the brief, together with the need for deterrence, was enough.

The rules that apply to a sponsor

Section 130-1.1(b) permits a sanction “upon any attorney appearing in the action or upon a partnership, firm or corporation with which the attorney is associated.” Section 130-1.1a(b) ties the certification to the act of signing. Section 520.11(c) makes the New York sponsor the attorney of record. And where a judge has adopted the model rule in Appendix A to 22 NYCRR Part 161, signing a paper prepared with an AI tool certifies that the paper was carefully reviewed and contains no fabricated or fictitious cases, statutes, or other material. Our guide to the New York AI disclosure rules covers Part 161 in full.

As of October 2026, we have not found a reported New York state decision sanctioning a pro hac vice sponsor for AI-fabricated citations in a brief written by out-of-state counsel. The rules above point in one direction, and the federal cases show where it leads.

What This Means for Out-of-State Counsel and Their New York Sponsor

1. In New York Supreme Court, your New York sponsor is attorney of record. Section 520.11(c) requires it for pre-trial and trial proceedings. Expect your New York attorney to read the papers before they are filed, and send drafts early enough for that to happen.
2. In the Southern and Eastern Districts, check whose name is on the paper. Local Civil Rule 1.3 does not require an attorney admitted pro hac vice to associate with local counsel at all. Rule 11 reaches whoever signs or presents the paper, so if local counsel's name is on it, local counsel owns it.
3. Never let anyone add your signature to a paper you have not read. In Wadsworth and Williams, local counsel was fined for papers filed over a signature someone else applied. In Johnson, the lawyers who were released had never authorized the use of their names.
4. Verify every citation against the source, whether or not anyone used AI. The duty comes from Rule 11 and Part 130, not from any AI-specific rule. Pull each case, confirm it exists, and confirm it says what the brief says it says.
5. Assume a sanction will follow you. Wilder shows that a Rule 11 finding for signing an AI brief can be the reason a later pro hac vice application is denied.

Frequently Asked Questions

Is local counsel responsible for AI-fabricated citations in a brief written by out-of-state counsel?

If local counsel signed or filed the brief, yes. Rule 11(b) attaches the certification to any attorney who presents a paper to the court by signing, filing, submitting, or later advocating it, and the Supreme Court has held that responsibility is personal and nondelegable. In Wadsworth v. Walmart Inc. (D. Wyo. 2025), local counsel who did not draft the motions or review them before filing was fined $1,000 under Rule 11(b)(2). In Versant Funding v. Teras Breakbulk (S.D. Fla. 2025), local counsel who signed and filed a response drafted by pro hac vice counsel was fined, made jointly liable for fees, and ordered to complete AI training.

Does a pro hac vice sponsor have to be attorney of record in New York state court?

Yes, for pre-trial and trial proceedings. 22 NYCRR 520.11(c) provides that no attorney may be admitted pro hac vice to participate in pre-trial or trial proceedings unless associated with a member in good standing of the New York bar, who shall be the attorney of record in the matter. Under 22 NYCRR 130-1.1a(b), signing a paper certifies that it is not frivolous after an inquiry reasonable under the circumstances.

Do the Southern and Eastern Districts of New York require local counsel after pro hac vice admission?

No. Local Civil Rule 1.3, which governs pro hac vice admission in both districts, does not require an admitted attorney to associate with local counsel. Local counsel's exposure in those courts therefore turns on whether local counsel signs or presents the paper, because Rule 11 applies to whoever does.

Can a sanction for AI citations affect a later pro hac vice application?

Yes. In Wilder v. President and Fellows of Harvard College (Mass. Super. Ct. 2026), the court denied a lawyer's pro hac vice application in part because of a Rule 11 sanction he received for signing motions containing AI-fabricated citations and because he had not shown that he had changed his practice of reviewing papers filed over his signature. It later refused to vacate that denial.

Has any court excused a co-signer who did not write the brief?

Some have. In Johnson v. Dunn (N.D. Ala. 2025), two lawyers named in the signature block were released because they had not drafted, revised, or reviewed the motions, had no supervisory role, and had not delegated the use of their signatures. In United States v. Cohen (S.D.N.Y. 2024), the court declined to sanction counsel who did not review citations he believed came from co-counsel, because a sanction raised by the court on its own initiative requires subjective bad faith in the Second Circuit. Neither case protects a lawyer who signed without reading.

Related: AI Disclosure Rules in New York Courts · Are AI Prompts Privileged or Discoverable? · Pro Hac Vice Overview · New York Local Counsel · Do You Need Local Counsel? · PHV in SDNY and EDNY

This article is general information, not legal advice. It describes decisions and rules as of October 2026. Courts continue to decide cases in this area, so confirm the current law and the assigned judge's rules before relying on any of it. Attorney advertising.