MO HB2666

Replaces Missouri's existing anti-SLAPP law (section 537.528) with the "Uniform Public Expression Protection Act" (section 537.529), providing broader protections against lawsuits targeting free speech, press, assembly, petition, and association rights on matters of public concern

Allows defendants to file a special motion to dismiss within 60 days of being served, which automatically stays all discovery and proceedings until the court rules and any appeals are exhausted

Requires courts to dismiss claims with prejudice if the defendant shows the law applies and the plaintiff fails to establish either a prima facie case or that an exemption applies (such as suits against government units or claims against businesses over commercial speech)

Mandates courts award costs, reasonable attorney's fees, and litigation expenses to the prevailing moving party, or to the responding party if the motion was frivolous or filed solely to delay

Applies to civil actions filed on or after August 28, 2026, and includes a 21-day right of appeal from orders denying dismissal motions