Wilson v. United States, 2023 U . S . App. LEXIS 21864 (August 21, 2023) (Chagares, C.J.) Marquis Wilson challenges the District Court’s grant of summary judgment to the Government in his Federal Tort Claims Act (“FTCA”) lawsuit for medical negligence. The dispositive issue here is whether Pennsylvania Rule of Civil Procedure 1042.3 (“Rule 1042.3”), which requires medical malpractice plaintiffs to certify either that they have expert support for their claims or instead will proceed without an expert, applies in FTCA cases like Wilson’s. The grant of summary judgment here was predicated upon Wilson’s Rule 1042.3 certification to proceed without an expert to support his claim. Because we interpret the FTCA not to incorporate Rule 1042.3, and because Wilson did not otherwise have an adequate opportunity to seek out an expert or conduct discovery prior to the District Court’s decision due to his unique position as a pro se inmate during the COVID-19 pandemic, we will reverse the grant of summary judgment and remand this case to the District Court. We hold that Rule 1042.3’s certificate of merit requirement does not apply in FTCA cases. The FTCA’s incorporation of state law is limited in scope and reaches only a subset of potentially relevant state legal rules. The Supreme Court has instructed that “§ 1346(b)’s reference to the ‘law of the place’ means law of the State-the source of substantive liability under the FTCA.” F.D.I.C. v. Meyer, 510 U.S. 471, 478, 114 S. Ct. 996, 127 L. Ed. 2d 308 (1994) (emphasis added). We have in turn interpreted Meyer and its progeny to mean that state law supplies “[t]he cause of action in an FTCA claim.” Just because a state rule of civil procedure is outcome determinative does not necessarily mean that it informs the state law merits-based liability determination as required for FTCA incorporation. As other Courts of Appeals have recognized in similar cases, failing to apply a state certificate of merit rule in an FTCA case “may mean that fewer complaints are dismissed as ‘procedurally defective,’ but it will do ‘nothing to change the scope of the Government’s liability’ because state law continues to supply the ‘rules of decision.'” Pledger v. Lynch, 5 F.4th 511, 522-23 (4th Cir. 2021) (quoting Gallivan v. United States, 943 F.3d 291, 295 (6th Cir. 2019)). Rule 1042.3 “neither modifies [the common law] standard of liability nor elucidates the types of evidence required to establish the standard, its breach, or causality. The [expert] opinion required by [Rule 1042.3] does not ‘play any role in the post-complaint adjudication of a medical malpractice claim.'” Corley v. United States, 11 F.4th 79, 86 (2d Cir. 2021) (quoting Shields v. United States, 436 F. Supp. 3d 540, 542 n.2 (D. Conn. 2020)). It is therefore not a rule of tort liability incorporated by the FTCA, even if it may be “substantive” for the purposes of Erie. Congress has chosen to supplant certain aspects of state law rules of decision in FTCA cases. See Supreme Beef, 468 F.3d at 252 n.4 (noting that Congress has imposed “substantive limits on t[he] incorporation” of state law in FTCA cases, including the “discretionary function and intentional tort exceptions to the FTCA”). For the foregoing reasons, we will reverse the grant of summary judgment and remand to the District Court for further proceedings.