Montana has 64 contested state legislative primaries in 2026, up 8% from 2024 and the highest number at any point since 2010.
Of these, there are 20 for Democrats and 44 for Republicans. For Democrats, this is up from 15 in 2024, a 33% increase. The number of contested Republican primaries in 2026 is the same as in 2024.
Twenty-three Montana state legislative incumbents face primary contests in 2026, the same as in 2020, and tied for second most at any point since 2010. This is a 4% decrease in the number of incumbents facing challengers compared to 2024.
Three of the contested incumbents are Democrats, and 20 are Republicans. Nineteen are state representatives, and four are state senators.
In total, 311 major party candidates filed to run. One hundred forty-five are Democrats, and 166 are Republicans. All 100 House seats and 25 of 50 Senate seats are up for election.
Thirty-nine seats are open, meaning no incumbents filed. This means newcomers will make up at least 26% of the legislature next year. The average number of open seats each cycle from 2010 to 2024 was 44.
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