- Democratic congressional and state primaries: open
- Republican congressional and state primaries: open
- Democratic Presidential primary: open
- Republican Presidential primary: open
- Wisconsin has nonpartisan registration. There is no option to affiliate with a political party on the voter registration form.
Details of voting in congressional and state primary elections:
- Voters do not declare affiliation with a party in order to vote, but they must choose one party's ballot.
- Voters are not tied to that party affiliation in the future.