In Missouri, a party can intervene in a lawsuit as of right or permissibly. Each has specific requirements. Only “final judgments” — those resolving all issues in a lawsuit — can be appealed.
Motions to intervene can affect the finality of judgments in relation to appeals. Judgments do not rule on motions sub silentio. Howe v. Heartland Midwest, LLC, 604 S.W.3d 774, 779 (Mo. App. W.D. 2020). “Sub silentio” means without notice or implicitly. “Trial courts are typically required to address all pending motions, including a motion to intervene as a matter of right under Rule 52.12(a)(2).” MILA Homes, LLC v. Scott, 608 S.W.3d 658, 662 fn5 (Mo. App. W.D. 2020). Taken together, then, a failure to rule on a motion to intervene renders the judgment not final. Id. at 662 fn5.