Overruling Batzel v. Smith, 333 F.3d 1018 (9th Cir. 2003), and dismissing an appeal for lack of jurisdiction, the en banc court held that a district court’s denial of a motion to strike under the California anti-SLAPP statute does not satisfy the requirements for an interlocutory appeal under the collateral order doctrine.

Agreeing with other circuits, the en banc court held that orders denying anti-SLAPP motions under California’s statute are not immediately appealable because such orders do not resolve issues “completely separate from the merits of the action” and do not render the decision “effectively unreviewable on appeal from a final judgment.”

For purposes of this opinion, the en banc court assumed that California’s anti-SLAPP statute applies in federal court.

Concurring, Judge Bennett, joined by Judge Callahan, wrote that he joined the majority opinion in full and wrote separately to state that California’s anti-SLAPP special-motion and attorney-fee-shifting provision create a substantive right, and no federal rule controls or directly collides with that right. Thus, the anti-SLAPP provisions apply in federal court under Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938), and its progeny.

Concurring in the judgment, Judge Bress, joined by Judges Collins, Lee, and Bumatay, wrote that it would have been better for the en banc court to address the issue of federal-court application, join the overwhelming majority view, and hold that California’s anti-SLAPP statute is a state procedural device that does not apply in federal court.

https://cdn.ca9.uscourts.gov/datastore/opinions/2025/10/09/24-2626.pdf