Guidelines for “Discovery on Discovery”

While disfavored, relevant and proportional “discovery on discovery” is permitted “where there is evidence of a specific deficiency in the production.”  Allergan, Inc. v. Revance Therapeutics, Inc., 2025 WL 2187115 (M.D. Tenn. Jul. 25, 2025).

Revance moved to compel Allergan “to more fully respond to discovery related to former Allergan and former Revance employee Derek Chan.”  Mr. Chan left Allergan to work for Revance and later returned to Allergan.  Revance posed five questions to Allergan:

1. Produce all document retention policies applicable to the preservation of Mr. Chan’s Allergan/AbbVie ESI/mailbox data (from 2015 – present). This should include, at a minimum, the Global Records and Personal Data Retention Policy; the Global Records Retention Policy, and Corporate Records Retention Policy.
2. Explain the reason why Allergan no longer possesses Mr. Chan’s custodial mailbox.
3. Identify when Allergan ceased to possess/have access to Mr. Chan’s custodial mailbox.
4. Identify all “other custodians who communicated with Derek Chan” from whom Allergan says it has collected emails involving Mr. Chan. In other words, disclose the custodians’ mailboxes that Allergan searched to locate his emails.
5. Identify any other agreed-upon custodian for whom Allergan lacks custodial mailbox data.

The Allergan court’s description of the standard for discovery on discovery was clear and succinct:

Federal Rule of Civil Procedure 26(b)(1) also contemplates that, in appropriate circumstances, one party may seek information about another party’s retention efforts. Fed. R. Civ. P. 26(b)(1) Adv. Comm. Notes (stating that discovery may include information about the “custody, condition, and location of any documents” and “detailed information about another party’s information systems and other information sources,” so long as “relevant and proportional to the needs of the case”); see Ruiz-Bueno v. Scott, No. 2:12-CV-0809, 2013 WL 6055402, at *1 (S.D. Ohio Nov. 15, 2013) (“Sometimes, information about discovery is a matter which ‘may aid a party in the preparation … of his case.’ When that is true, that information is relevant within the meaning of Rule 26(b).”). But this so-called “discovery on discovery” is not automatic and courts typically disfavor it. See, e.g., Buergofol GmbH v. Omega Liner Co., Inc., No. 4:22-CV-04112-KES, 2024 WL 4291467, at *7 (D.S.D. Sept. 25, 2024).

Despite the disfavor, courts have permitted this type of discovery “where there is evidence of a specific deficiency in the production.” Culliver v. BP Exploration & Prod., Inc., No. 21-cv-4942-MCR-HTC, 2022 WL 19568966, at *2 (N.D. Fla. Nov. 29, 2022) (citations omitted); Stein v. U.S. Xpress Enters., Inc., No. 19-CV-00098-TRM-CHS, 2022 WL 511553, at *3 (E.D. Tenn. Feb. 11, 2022) (denying “discovery on discovery deposition” where the moving party had not “demonstrated any preservation lapse or productions issues that would call into question Defendants’ preservation and production efforts” (cleaned up)). To secure relief, the party seeking discovery must explain in sufficient factual detail the alleged deficiency in its opponent’s production or the type of evidence the opponent lost or failed to preserve. Conclusory assertions, suspicions that an opponent’s production is incomplete, and speculation of wrongdoing are insufficient to warrant additional discovery. Culliver, 2022 WL 19568966, at *2. Here, Revance slightly crosses this threshold because Allergan does not have access to Mr. Chan’s entire email database and therefore Revance should receive the limited discovery described below.

Applying these principles, the Allergan court addressed Revance’s five requests.

Allergan had produced, and agreed to produce, document retention policies.  It was also ordered to produce its timelines for retention and destruction, as well as historical policies.

Revance’s request for an explanation of why Allergan no longer possesses Mr. Chan’s mailbox was denied as moot: “Allergan explains that Mr. Chan was not put on a legal hold for this case because he had left Allergan almost three years before Allergan sued, and Allergan only learned of potential issues with Mr. Chan during discovery, which is why he was not named in the Complaint.”

Revance asked Allergan to identify the custodians it searched to locate Mr. Chan’s emails.  The court saw no evidence that this would be burdensome and ordered the relief.

Lastly, Revance asked Allergan to identify any custodians for whom it lacks mailbox data.

Allergan responds that it is “not aware” of inaccessible custodial mailbox data for the 25 agreed-upon custodians. The Special Master accepts Allergan’s representation and denies the request. Going forward, if either party learns that it no longer has full access to an agreed-upon custodian’s mailbox, it is ordered to disclose that information to the other party immediately.

Special Master Todd Presnell then proceeded to consider several RFP’s and Allergan’s objections.

For more information about “discovery on discovery,” aka “satellite discovery” or “culpability discovery,” please see:

• Request for “Discovery on Discovery” Was Overbroad; Uber Deponent Was Ordered to Bring Uber Laptop to Deposition; Discovery About Uber Information Governance Training Resolved (Jul. 4, 2025) (and multiple blogs cited in that blog);;

• The Hon. Paul W. Grimm, Michael D. Berman, et al., “Discovery About Discovery: Does the Attorney-Client Privilege Protect All Attorney-Client Communications Relating to the Preservation of Potentially Relevant Information?,” 37 U. Balt. L. Rev. 413 (2008).

• The Hon. Craig B. Shaffer, “Deconstructing ‘Discovery About Discovery,’’ 19 Sedona Conf. L.J. 215 (2018)(‘ In short, the phrase ‘discovery about discovery’ should be abandoned by parties and courts in favor of informed and reasonable case management. That analysis should distinguish between ‘‘merits-directed discovery’ and ‘process-directed discovery.’ Discovery directed to the merits of the litigation, as a threshold matter, should be framed by the specific elements underlying the claims and defenses advanced by the parties, and focus on issues germane to settlement, dispositive motions, or trial. ‘Process-directed discovery,’ on the other hand, is directed to the manner and efficacy of the production process itself, as measured by Rules 1, 26(b)(1), 26(b)(2)(B), 26(b)(2)(C), and 26(g). Discovery directed toward ESI and the information gathering and production process should be addressed within the context of the Federal Rules of Civil Procedure, with due consideration for evolving case law and the litigants’ strategic interests.”).

Judge Shaffer concluded that: “In the final analysis, a party seeking process-directed discovery must determine whether and to what extent additional information will materially advance the ultimate disposition of the action. Discovery about discovery is not a substitute for an informed and strategic application of the Federal Rules of Civil Procedure.”