{"data":{"id":"us-mo/mo.-rev.-stat.-509.450","jurisdiction":"us-mo","citation":"Mo. Rev. Stat. § 509.450","heading":"Counterclaim set up by amendment, when.","body":"When a pleader fails to set up a counterclaim through oversight, inadvertence, or excusable neglect, or when justice requires he may by leave of court set up the counterclaim by amendment.","path":["Title XXXV - CIVIL PROCEDURE AND LIMITATIONS","Chapter 509 - Pleadings"],"source_url":"https://revisor.mo.gov/main/OneSection.aspx?section=509.450","current_through":"2026 legislative session (floor)","vintage":"","retrieved_at":"2026-09-03T22:23:28Z","sha256":"bc53fe84cb3ea127d3229d4b1b112264a39fa807e97bf880034abf2fc64898e8","source_id":"us-mo","stale":false,"prev":"us-mo/mo.-rev.-stat.-509.440","next":"us-mo/mo.-rev.-stat.-509.460"},"notice":"GroundRules: Original legal text. Not legal advice."}