Term limits will trigger major turnover in the state House in the November election.
Forty-four of the chamber's 110 seats will be open because the incumbent lawmakers aren't allowed to run again.
One more seat will be open because an incumbent eligible for re-election isn't running.
Dozens of newcomers registered to run for the open seats before Tuesday afternoon's filing deadline. That sets the stage for crowded August primaries in some districts.
Michigan law limits state House members to three terms of two years each.
Democrats hold a 58-52 edge over Republicans in the House and could be helped by the upcoming turnover because more seats now held by Republicans will be vacated.