Chapter 02 / Open primary states
Top 10 open primary states, and every state with open primaries in 2026
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Which states have open primaries in 2026?
In 2026, 19 states hold open primaries with no party registration, and 3 more hold nonpartisan primaries open to every voter.
Primary Field Guide counts 22 states where any registered voter can vote in the primary without joining a party. The top 10 open primary states below are ranked by the share of voters outside both major parties, because that is where open access matters most. Hawaii leads, with 48.77 percent of voters independent.
Open primary definition
An open primary is a primary election in which any registered voter may take part without first joining a political party. In most open states, voters pick one party’s ballot privately at the polls. Primary Field Guide treats nonpartisan top-two and top-four primaries as the fullest form of open primary, because every voter gets the same ballot and no party choice is needed at all.
Open primaries are different from semi-open systems, where the ballot choice may be recorded, and from semi-closed systems, where only unaffiliated voters can choose.
Top 10 open primary states, ranked
| Rank and state | Independent share | How the primary works |
|---|---|---|
| 01 Hawaii | 48.77% | Nearly half of voters sit outside both major parties, and any voter can choose a party ballot. |
| 02 Mississippi | 47.27% | No party registration, so independents are never shut out of the primary. |
| 03 Arkansas | 40.45% | Four in ten voters show no party tie, and every voter may pick a primary. |
| 04 Montana | 29.07% | Voters choose a party ballot privately in the booth. |
| 05 Georgia | 28.89% | Any voter can request a party ballot; runoffs follow the voter’s first choice. |
| 06 North Dakota | 28.4% | The only state with no voter registration at all, so no party gate exists. |
| 07 Minnesota | 28.08% | Voters pick one party’s column on a single primary ballot. |
| 08 Missouri | 17.23% | Voters ask for the party ballot they want at the polls. |
| 09 Michigan | 16.85% | One ballot lists every party; voters mark candidates from one party only. |
| 10 Alabama | 8.46% | Open primary, though a voter who picks one party cannot switch for that party’s runoff. |
Independent shares are updated November 2026. In states without party registration, such as Alabama, shares are modeled.
How many states have open primaries?
22 states let every voter take part: 19 traditional open primary states plus 3 nonpartisan states. Another 14 systems are partly open, letting unaffiliated voters choose a party ballot, and 15 states are fully closed.
- Nonpartisan
- 3
- Open
- 19
- Partly open
- 14
- Closed
- 15
Counts include Washington, D.C. Other sources may count semi-open states as open.
Every state with open primaries in 2026
Nonpartisan, open to every voter on one ballot
Alaska, California, Washington.
Open primary, no party registration required
Alabama, Arkansas, Georgia, Hawaii, Illinois, Indiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, Ohio, South Carolina, Tennessee, Texas, Vermont, Virginia, Wisconsin.
- Nonpartisan top-two or top-four (3)
- Open or partially open, no party registration (19)
- Partly open: unaffiliated voters may pick a ballot (14)
- Closed: party members only (15)
What changes outside open primary states
Outside open states, party rules and deadlines decide who votes. Ballotpedia’s primary election types by state table records rules such as a voter needing to affiliate with a party 29 days before the primary, or staying affiliated for at least 3 months before switching. In one state it lists, a voter who leaves a party cannot vote in any partisan primary for 3 months afterward.
Open primaries remove those hurdles. That is why the open primaries for every voter campaign targets closed systems first. Compare systems in open vs closed primaries or go back to the best primary systems 2026 rankings.
Methodology
We ranked the top 10 open primary states by the share of registered or modeled independent voters, since those voters benefit most when a primary is open. Every entry is judged on the same criteria using published state election rules and the named sources on this page. We did not run our own surveys or polls. Read how we rank primary systems for the full approach.
Common questions
- Which states have open primaries in 2026?
- In 2026, 19 states run open or partially open primaries with no party registration: Alabama, Arkansas, Georgia, Hawaii, Illinois, Indiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, Ohio, South Carolina, Tennessee, Texas, Vermont, Virginia, and Wisconsin. California, Washington, and Alaska go further with nonpartisan primaries open to every voter on one ballot.See this answer in the full FAQ
- How many states have open primaries?
- By this guide’s count, 22 states let every voter take part in the primary: 19 open or partially open states plus the three nonpartisan states, California, Washington, and Alaska. Counts elsewhere run higher or lower because some sources add semi-open states. Always check your own state’s election office for current rules.See this answer in the full FAQ
- What is the open primary definition in simple terms?
- In simple terms, an open primary lets you vote in the primary no matter which party you belong to, or whether you belong to one at all. Your party registration, if your state even has one, does not decide whether you get a ballot. The details, such as whether your ballot choice is recorded, vary by state.See this answer in the full FAQ
- Do I have to declare a party to vote in an open primary?
- No, you do not have to join a party to vote in an open primary. In most open states you choose a party ballot privately at the polls. In semi-open states your choice may be recorded publicly. In nonpartisan top-two states, there is no party choice at all, because everyone gets the same ballot.See this answer in the full FAQ
- Can independent voters vote in primaries?
- Independent voters can vote in primaries in most states, but not in the 15 closed-primary states. In open and nonpartisan states they vote freely. In semi-closed and semi-open states they can usually choose a party ballot. 66,284,669 Americans are registered in states that keep them out of primaries.See this answer in the full FAQ
- What is a semi-open primary?
- A semi-open primary lets any voter request a party ballot, but the choice may be publicly recorded. Colorado and Arizona are classified this way in state data. It is more inclusive than a closed system, though a recorded ballot choice can feel like a public statement of party preference.See this answer in the full FAQ
Your next step
Start with open primaries. Then explore More Choice Voting.
Getting every voter a primary ballot is the first barrier to clear. The Independent Voter Project runs the national campaign for open primaries for every voter, and our More Choice Voting chapter covers what comes after.