- May 2 - McCulloch to Check Voter Registration and Cast an Absentee Ballot
- May 7 - Absentee Voting Opens for Montana’s 2012 Primary Election; Counties Mail Record Number of Ballots to State’s Identified Absentee Voters
- May 15 - Redefining the "MVP"
- May 22 - Secretary McCulloch Reminds Montanans to Return Absentee Ballots for Primary; Absentee Ballots Due by 8:00 p.m. on Election Day
- May 29 - McCulloch Reminds Absentee Voters to Be Mindful of Mail Delivery Standards When Returning Ballots
- May 31 - AutoMARK Voting Machines Available For
Individuals With Visual and Mobility Impairments