With mass tort cases on the rise, one increasingly common form of relief plaintiffs seek is “medical monitoring,” where the defendants pay for plaintiffs’ consultations with doctors to detect potentially latent conditions or diseases, as in M.P. v. Allergan, No. 2:19-cv-22126 (D.N.J.) (Dec. 30, 2019); Doe v. Allergan, No. 2:19-cv-05138 (E.D. Pa.) (Nov. 1, 2019) and Banks v. E.I. du Pont de Nemours & Co., No. 1:19-cv-01672 (D. Del.) (May 17, 2019; removed Sept. 06, 2019). When plaintiffs seek certification of these so-called medical-monitoring classes, the courts face a threshold question: are medical-monitoring claims predominantly claims for injunctive relief, subject to the requirements of Rule 23(b)(2), or are they claims for monetary relief, subject to the requirements of Rule 23(b)(3)? Across the country, courts have long been “divided over whether Rule 23(b)(2) or Rule 23(b)(3) is the appropriate vehicle for certifying a mass tort class for medical monitoring,” see “Manual for Complex Litigation” (Fourth) Section 22.74 (2004).

The uncertainty about the rules governing certification of medical-monitoring classes is particularly acute in the U.S. Court of Appeals for the Third Circuit, which has twice taken the unusual step of granting Rule 23(f) petitions to consider the issue, only to leave it unresolved. See Gates v. Rohm & Haas, 655 F.3d 255, 263 (3d Cir. 2011) (“questioning” whether medical-monitoring claims could be certified under Rule 23(b)(2), but denying class certification for different reasons); Baker v. LivaNova, No. 17-8059 (3rd Cir. Dec. 13, 2018) (granting Rule 23(f) petition on this issue; case settled prior to briefing and argument).