Open Primary States 2026

Primary Type

Closed

Open w/ NR

Open w/ PR

State	Primary Type↓	Congressional/State	Presidential	System
Alabama	Open w/ NR	Open	Open	All voters must choose one party's ballot to vote on, but they are not tied to that party. But voters who do not participate in either primary will only be given the amendments/referendum ballot.
Arkansas	Open w/ NR	Open	Open	Each voter will be able to choose which ballot they vote on, but they will be held to that party in the case of a run-off. Unaffiliated voters that decide not to participate in either party's primary will receive the amendments/referendum ballot only.
Georgia	Open w/ NR	Open	Open	Georgia voters don't have to declare a party but must choose one party's ballot.
Illinois	Open w/ NR	Open	Open	Illinois voters do not have to register with a party, but they do have to choose one party's ballot to vote publically. The choice is legally considered a public declaration and can be challenged by other voters.
Indiana	Open w/ NR	Open	Open	While affiliation with a party is not required to vote in the primary, Indiana has laws of intent that impact your vote in the general election.
Michigan	Open w/ NR	Open	Open	Michigan voters do not declare affiliation but must choose a party's ballot to vote on.
Minnesota	Open w/ NR	Open	Open	Minnesota voters do not declare affiliation but must choose a party's ballot to vote on.
Mississippi	Open w/ NR	Open	Open	Mississippi voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Missouri	Open w/ NR	Open	Open	Missouri voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Montana	Open w/ NR	Open	Open	Montana voters do not declare affiliation, but they do have to choose a party's ballot to vote.
North Carolina	Open w/ NR	Open	Open	While voters aren't required to declare a party, they are required to choose one party's ballot to vote on.
Ohio	Open w/ NR	Open	Open	Each voter in Ohio chooses one party's ballot to vote on, and that choice determines their political affiliation.
South Carolina	Open w/ NR	Open	Open	South Carolina voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Tennessee	Open w/ NR	Open	Open	Tennessee voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Texas	Open w/ NR	Open	Open	Texas voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Vermont	Open w/ NR	Open	Open	Vermont voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Virginia	Open w/ NR	Open	Open	Virginia voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Wisconsin	Open w/ NR	Open	Open	Wisconsin voters do not ahev to declare affiliation, but they do have to choose a party's ballot to vote. This choice does not change their affiliation.
Colorado	Open w/ PR	Open	Open	Colorado voters don't have to declare a party but must choose one party's ballot.
Iowa	Open w/ PR	Open	Open	Iowa voters must be registered with a party to vote in the primary.
Kansas	Open w/ PR	Open	Open	While registered voters can participate in their party's primary, unaffiliated voters can declare their party the day of and vote on that ballot.
Massachusetts	Open w/ PR	Open	Open	Six months before the primary, each party has to notify the State Board of Elections if they are opening or closing their primary as state laws permit them to choose.
New Hampshire	Open w/ PR	Open	Open	New Hampshire voters must be affiliated to participate in a party's primary, while unaffiliated voters may choose one party's ballot to vote on. But that action makes them a member of the chosen ballot's party.
Rhode Island	Open w/ PR	Open	Open	All unaffiliated voters choose one party's ballot to cast their vote in the primary. This choice is viewed as a party declaration.
West Virginia	Open w/ PR	Open	Open	In West Virginia, parties decide who may participate in their primaries. As of 2022, both major parties allow unaffiliated voters to participate in their primaries. But party members must vote in their own primary.
Wyoming	Open w/ PR	Open	Open	Wyoming's voters must register with a party to vote in that party's primary, while unaffiliated voters may register with a party at the polls to vote in that party's primary.
Alaska	Closed	Open (Top-Four)	Closed	Voters may vote for one candidate per race without consideration for political affiliation. This includes nonpartisan and undeclared.
Arizona	Closed	Open to Unaffiliated	Closed	While party members may only vote on that ballot, unaffiliated voters may choose which ballot to vote on.
California	Closed	Top-Two	Closed	As of 2022, California is attempting a Top-Two system, where all registered voters receive one ballot regardless of party affiliation, and the top two move on to the general election.
Connecticut	Closed	Closed	Closed	Connecticut voters must declare a party in advance to vote in that party's primary.
Delaware	Closed	Closed	Closed	Delaware voters must declare a party in advance to vote in that party's primary.
Florida	Closed	Closed	Closed	Florida voters must declare a party in advance to vote in that party's primary.
Hawaii	Closed	Open	Closed	Hawaii voters don't have to declare a party but must choose one party's ballot.
Idaho	Closed	Closed	Closed	Voters must be a member of a party to participate in the primary. Parties may or may not open primaries to unaffiliated voters.
Kentucky	Closed	Closed	Closed	Kentucky party-affiliated voters can only vote in that party's primary.
Louisiana	Closed	N/A	Closed	Louisiana holds no primaries. They list all candidates on a single ballot, and all registered voters may participate.
Maine	Closed	Semi Open	Closed	In 2024, Maine voters can cast ballots in one party's primary without having to join that party.
Maryland	Closed	Closed	Closed	Six months before the primary, each party has to notify the State Board of Elections if they are opening or closing their primary as state laws permit them to choose.
Nebraska	Closed	Closed	Closed	Voters may or may not choose to affiliate with a political party. However, affiliation with a party is required to vote in certain primary elections.
Nevada	Closed	Closed	Closed	Nevada voters must be registered in a party to participate in the primary.
New Jersey	Closed	Closed	Closed	Voters must be a member of a party to participate in the primary.
New Mexico	Closed	Closed	Closed	New Mexican voters must be registered with a party in order to vote in a primary.
New York	Closed	Closed	Closed	Voters in New York must be a member of a party to participate in the primary.
North Dakota	Closed	Open	Closed	All candidates are listed on one ballot, which means party affiliation is not necessary to participate in the primary. Voters can only choose candidates from one party. (If they vote for more than one party, the ballot will be rejected.)
Oklahoma	Closed	Closed	Closed	Voters must be registered with a party to participate in their primary. In Oklahoma, Independent voters are allowed to participate in Democratic primaries, but not Republican.
Oregon	Closed	Closed	Closed	Oregon voters must be registered with a party to participate in the primary.
Pennsylvania	Closed	Closed	Closed	Pennsylvania voters must be registered with a party to participate in the primary.
South Dakota	Closed	Closed	Closed	Voters must be registered with a party to participate in their primary. In South Dakota, unaffiliated voters can participate in Democratic primaries without changing their status. This does not apply to Republican primaries.
Utah	Closed	Closed	Closed	Voters must be registered with a party to participate in their primary. In Utah, unaffiliated voters can participate in Democratic primaries without changing their status. This does not apply to Republican primaries.
Washington	Closed	Open	Closed	Each voter receives the same primary ballot, using a top-two system, regardless of affiliation. The presidential primary, on the other hand, is closed.

Open Primary (No Registration) A primary system where voters do not need to register with a political party and may choose which party’s primary to vote in on election day.

Open Primary (With Registration) A primary system where voters must be registered with a party or declare affiliation, though unaffiliated voters may still have limited access.

Closed Primary System A primary system in which only voters registered with a political party may vote in that party’s primary election.

States With Open Primaries (No Party Registration Required)

Some states allow voters to participate in primary elections without registering with a political party. In these states, voters can choose which party’s primary to vote in on election day, but may only select one party’s ballot per election cycle.

These states are Alabama, Arkansas, Georgia, Illinois, Indiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Carolina, Ohio, South Carolina, Tennessee, Texas, Vermont, Virginia, and Wisconsin.

States With Open Primaries (Party Registration Required)

Some states allow open participation in primaries but require voters to be registered with a political party or to declare affiliation before voting. In many cases, unaffiliated voters can still participate by selecting or temporarily adopting a party at the time of voting.

These states are Colorado, Iowa, Kansas, Massachusetts, New Hampshire, Rhode Island, West Virginia, and Wyoming.

States With Closed Primaries

Many states use closed primary systems, where only voters registered with a political party may participate in that party’s primary election. In these states, voters must be registered with a political party and are limited to voting within their chosen party.

These states are Alaska, Arizona, California, Connecticut, Delaware, Florida, Hawaii, Idaho, Kentucky, Louisiana, Maine, Maryland, Nebraska, Nevada, New Jersey, New Mexico, New York, North Dakota, Oklahoma, Oregon, Pennsylvania, South Dakota, Utah, and Washington.

States With Top-Two or Nontraditional Primary Systems

A few states use primary systems that do not follow the traditional open or closed model. These systems often place all candidates on a single ballot, regardless of party affiliation, and advance the top candidates to the general election based on vote totals.

States with these systems include California and Washington, which use a top-two primary, Alaska, which uses a top-four system for certain elections, and Louisiana, which does not hold traditional primaries and instead places all candidates on a single general election ballot.

Key Differences in Primary Election Rules

Primary election rules can vary significantly even within the same state. Some states allow unaffiliated voters to participate freely, while others require party registration or limit access depending on the election type. In certain cases, rules differ between presidential primaries and state or congressional primaries.

Political parties may also have control over who can participate in their primaries, particularly in states with more flexible systems. As a result, voter eligibility, ballot access, and participation rules can change over time or differ based on party decisions.