Why Forum Matters More After Berk v. Choy
A case filed in state court may look very different from one that lands in federal court on diversity grounds. The Supreme Court’s recent decision in Berk v. Choy, 607 U.S. 187 (2026) underscores that familiar state-court requirements may give way when a Federal Rule of Civil Procedure answers the same question.
Before Berk, the governing framework was shaped by Shady Grove Orthopedic Associates, P.A. v. Allstate Insurance Co., 559 U.S. 393, 398 (2010). Under Shady Grove, the first question was whether a Federal Rule “answers the question in dispute.” If it did, the Federal Rule governed unless it exceeded statutory authorization or Congress’s rulemaking power. For the latter, the focus was on whether the Federal Rule “really regulates procedure,” not on whether the displaced state rule served a substantive purpose. If no Federal Rule answered the question, courts then moved to the familiar analysis from Erie R. Co. v. Tompkins, 304 U.S. 64, 78 (1938) and asked whether the state requirement was “substantive,” including whether ignoring it would affect outcomes, encourage forum shopping, or create inequitable administration of the laws. That is how the Third Circuit analyzed Delaware’s affidavit-of-merit statute before the Supreme Court reversed.
Berk clarified how the threshold question should be applied. When a valid Federal Rule is on point, the court does not proceed through Erie’s “murky waters.” It applies the Federal Rule even if the state rule might otherwise be considered substantive. Applying that principle, the Court held that Delaware’s medical-malpractice affidavit requirement did not apply in federal court because Rule 8 answered the relevant pleading question and displaced the contrary state requirement.
In Michigan, the same reasoning may call into question whether the state affidavit-of-merit requirement for medical-malpractice cases applies in diversity cases filed in or removed to federal court. Another example is Michigan Court Rule 2.112(K), which governs notices of nonparty fault in state court. In state court, the notice procedure is critical to preserving a defendant’s ability to have fault allocated to a nonparty. After Berk, however, federal courts may first ask whether the Federal Rules already answer the question that the Michigan rule addresses.
The Eastern District of Michigan’s recent decision in Earehart v. Peerless Chain Co., 2026 WL 1347415 (E.D. Mich. 2026) illustrates the issue. There, the defendant removed a products-liability case and later filed notices of nonparty fault under MCR 2.112(K). The plaintiff moved to dismiss or strike a notice under Rules 12(b)(6) and 12(f), but the court denied the motion because a notice of nonparty fault is not a “pleading” under Federal Rule 7(a). More significantly, the court observed that nonparty fault is an affirmative defense governed in federal court by Rule 8(c). Reading Berk to mean that Rule 8 sets the ceiling for affirmative-defense pleading absent a specific Rule 9 requirement, the court suggested that MCR 2.112(K) cannot be used either to impose extra requirements on federal defendants or to bypass Rule 8.
Other recent decisions point in the same direction. In AHC Holdings, Inc. v. MSU Health Care, Inc., — F.Supp.3d – (W.D. Mich. 2026) the Western District held that Rules 8 and 9 – not Michigan’s heightened defamation pleading standard – governed the sufficiency of a defamation complaint in federal court, and it rejected forum-shopping arguments because Berk allows the Civil Rules to “skip” that Erie analysis. In Oldnar Corp. v. Sanyo North America Corp., 2026 WL 1304394 (6th Cir. 2026), the Sixth Circuit cited Berk in holding that Federal Rule 68 displaced Michigan’s offer-of-judgment rule, MCR 2.405, on attorney-fee recovery because the federal rule answered the relevant costs question and the Michigan rule was procedural.
Under Berk, forum matters, and early case planning is important. It means evaluating nonparty-fault allegations, affirmative defenses, expert-affidavit requirements, and other state procedural mechanisms at the outset of the case. Decisions about filing, removal, and remand may now carry consequences beyond forum preference.