MT SB129

Allows Montana voters to add a political party affiliation to their voter registration when completing the standard application form or at any time after registering

Party affiliation options include each political party qualified under state law (13-10-601), "other party affiliation," and "prefer not to answer"

Requires voter registration lists and precinct registers to display electors' political party affiliation alongside their names and addresses if the information is included in their voter record

Replaces a fixed list of specific parties (Democratic, Green, Libertarian, Republican) with a dynamic reference to all qualified political parties under Montana law

Effective date changed from immediate upon passage to January 1, 2026