Montana Public Broadcasting Service will host two events that will be televised across the state.
Democratic Sen. Jon Tester will debate Republican challenger Matt Rosendale on Sept. 29 in Missoula.
Republican Rep. Greg Gianforte will debate Democratic challenger Kathleen Williams on Oct. 6 in Bozeman.
The debates will be held inside studios without an audience. Montana PBS producer John Twiggs and journalist Anna Rau will moderate the debates.
The debates will also air on Montana Public Radio on the days after the events.