You do not need to register as Democratic or Republican to vote in the primaries for these parties. In Massachusetts, unenrolled voters are allowed to vote in party primaries.
- Libertarian Party (24,000 members)
- Green-Rainbow Party (6,728 members)
- Working Families Party (5,534 members)
- New American Independent Party (3,000 members)
- Massachusetts Pirate Party
- Others on Secretary of State website