Parties resisting arbitration sometimes claim that compelling arbitration would result in “piecemeal” litigation because some claims are arbitrable and some are not. The U.S. Supreme Court, however, has made it clear (again) that courts cannot refuse to compel arbitration merely because some claims are arbitrable and some are not.
In KPMG LLP v. Cocchi, the Court reiterated that “when a complaint contains both arbitrable and nonarbitrable claims, the [FAA] requires courts to ‘compel arbitration of pendent arbitrable claims…, even where the result would be the possibly inefficient maintenance of separate proceedings in different forums.'” You can practically hear them sigh at having to keep saying this. Notably, this applies in both state and federal courts, so the FAA is sort of like the 8th Rule of Fight Club: “If a claim is arbitrable, you have to arbitrate.”