Guide to Semi-Open Primaries

Quick Summary

Did you know that Maine now has semi-open primaries? It’s important to know that unenrolled voters can now vote in the primary of their choice.

How to Vote in Maine


June 11 Voter Guide

Mainers will vote in a semi-open primary and use Ranked Choice Voting in statewide primaries. Here’s our complete guide to the June election.


Currently, there are five qualified political parties in Maine:

  1. Democratic
  2. Green Independent
  3. Libertarian
  4. No Labels
  5. Republican

You can enroll in one of these parties when you register to vote or when you need/want to update your voter registration.

Maine has a large population of voters (33% of all registered voters) who don’t choose a political party and register as “unenrolled.”

Semi-open primaries were implemented in time for the March presidential primary election in 2024. For the first time, unenrolled voters were permitted to cast one ballot in the primary of their choice.

Independent voters may think of themselves as unenrolled, but “Green Independent” is a qualified political party.

*Voters don’t need to be enrolled in a party to vote in a general election, on any statewide ballot question, or in a municipal election.

Independent voters may think of themselves as unenrolled, but “Green Independent” and the "No Labels Party" are qualified political parties.

Since presidential primaries are typically, if not always, Democratic and Republican, Green Independents and No Labels will have to switch parties or unenroll in order to participate in the primary.

Republicans will not be able to vote in Democratic primaries, and Democrats will not be able to vote in Republican primaries.

If you’re already registered to vote but want to switch your political party, you must re-register at least 15 days before election day.

Want to switch again? You can change your political party 3 months after your last registration date.

  • Enrolled voters — If you want to change political parties, you have until Friday, May 24, 2024 to update your registration in time for the primary election. Town offices will be closed for Memorial Day on the normal cut-off date, May 27. Your Town Office may also be closed on Fridays, so be sure to check the hours before visiting.
  • Unenrolled voters — At the polls, or when you request your absentee ballot, you can choose which primary that you want to vote in. Although you will cast your ballot in a party primary, you will maintain your unenrolled status.

Anytime is a good time to register to vote in Maine.

You can register to vote right up to and on Election Day. There is no cut-off date for registering to vote in-person at your town office or city hall. On Election Day, you can register right at your polling place! When you register to vote, you can either choose one of the qualified parties or register as unenrolled.

How to Vote in Maine

You can check your party enrollment status by contacting your town clerk.

Use the Maine Voter Lookup Service to find your clerk’s contact information: