Open Primary States 2026

Primary Type

All-Comers/Open to Unaffiliated

Closed

Nonpartisan/Open

Open

Open to Unaffiliated

Partially Closed

Partially Open

Top-Four

Top-Two

State	Primary Type↓	Congressional/State	Presidential	System
Louisiana	All-Comers/Open to Unaffiliated	Semi Open	Partially Closed	Louisiana uses an all-comers (open) primary system, where all voters can vote for any candidate in the primary regardless of party affiliation, and the top candidates may advance or win depending on majority rules.
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.
Kentucky	Closed	Closed	Closed	Kentucky party-affiliated voters can only vote in that party's primary.
New Jersey	Closed	Closed	Closed	Voters must be a member of a party to participate in the primary.
New York	Closed	Closed	Closed	Voters in New York must be a member of a party to participate in the primary.
Pennsylvania	Closed	Closed	Closed	Pennsylvania voters must be registered with a party to participate in the primary.
Tennessee	Closed	Open	Closed	Voters may participate in a party’s primary only if they are affiliated with that party or formally declare allegiance and intent to affiliate with it at the time of voting.
Wyoming	Closed	Closed	Closed	An elector must declare or change party affiliation before the primary filing period and only then may vote in that party’s primary, meaning participation is limited to voters who formally affiliate with a party.
Alaska	Top-Four	Open, All Candidates	Closed	Voters may vote for one candidate per race without consideration for political affiliation. This includes nonpartisan and undeclared.
California	Top-Two	Open, All Candidates	Partially 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.
Washington	Top-Two	Open, All Candidates	Open	Washington uses a top-two primary system, where all candidates appear on the same primary ballot regardless of party, and the two candidates receiving the most votes advance to the general election, regardless of party preference.
Connecticut	Partially Closed	Closed	Closed	Only voters enrolled in a party may vote in that party’s primary, while unaffiliated voters may participate only if permitted by party rules and must choose a single party’s primary when multiple are held.
Idaho	Partially Closed	Closed	Partially Closed	Idaho state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. (Open for Democratic Party)
Kansas	Partially Closed	Semi Open	Partially Open	Kansas state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. (Open (Democratic Party)
Maryland	Partially Closed	Closed	Partially Closed	A political party may choose whether to allow unaffiliated voters to participate in its primary election, meaning access for non-party voters depends on party rules rather than being uniformly open.
Oklahoma	Partially Closed	Closed	Partially Closed	A political party may choose to allow independent voters to participate in its primary election, meaning unaffiliated voter access depends on party permission rather than being automatically available.
Oregon	Partially Closed	Closed	Partially Closed	A political party may choose whether to allow unaffiliated voters to participate in its primary election, and may also limit which candidates those voters can select, meaning access for non-affiliated voters depends on party rules.
South Dakota	Partially Closed	Closed	Partially Closed	A political party may choose whether to allow unaffiliated voters to participate in its primary election, and may also limit which candidates those voters can select, meaning access for non-affiliated voters depends on party rules.
Utah	Partially Closed	Closed	Partially Closed	Utah state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. ((Open for Democratic Party)
West Virginia	Partially Closed	Closed	Partially Closed	Unaffiliated voters may participate in a party primary only if the political party allows it, while otherwise remaining limited to nonpartisan contests and public questions.
Illinois	Partially Open	Open	Partially Open	Voters must declare a party at the polling place and can only receive that party’s primary ballot, and those who refuse to state a party cannot vote in the primary. They may also participate in a local party primary if applicable, but cannot vote in more than one statewide party primary in the same election.
Indiana	Partially Open	Open	Partially Open	A voter may participate in a party’s primary only if they previously voted for, or intend to vote for, that party’s nominees in general elections, meaning access is tied to demonstrated party support rather than free choice at the primary.
Iowa	Partially Open	Open	Partially Open	Any registered voter may declare or change party affiliation at the polls on election day and then vote in that party’s primary, with the change recorded in official registration records.
Nevada	Partially Open	Closed	Partially Open	Voters declare a political affiliation at the polling place, and while party members are restricted to their own party’s primary, certain voters—such as those affiliated with minor parties—may receive a nonpartisan ballot instead of a partisan one.
Ohio	Partially Open	Open	Partially Open	Voters may request a party’s primary ballot by declaring support for that party, but eligibility can be challenged based on the voter’s recent primary voting history and party affiliation record.
Arizona	Open to Unaffiliated	Semi Open	Closed	While party members may only vote on that ballot, unaffiliated voters may choose which ballot to vote on.
Colorado	Open to Unaffiliated	Semi Open	Open to Unaffiliated	Unaffiliated voters in Colorado may vote in either party’s primary without registering with that party, but they must choose only one party ballot.
Maine	Open to Unaffiliated	Semi Open	Open to Unaffiliated	Unenrolled voters may participate in a party’s primary without enrolling in that party, but they may vote in only one party’s primary election.
Massachusetts	Open to Unaffiliated	Semi Open	Open to Unaffiliated	Massachusetts is a semi-closed primary, where unenrolled voters may choose a party’s primary ballot and registered party members vote only in their own party’s primary.
New Hampshire	Open to Unaffiliated	Semi Open	Open to Unaffiliated	Unaffiliated voters may choose a party’s primary ballot on election day and register with that party for the primary, with the option to return to undeclared status afterward.
New Mexico	Open to Unaffiliated	Semi Open	Open to Unaffiliated	A voter who is not affiliated with a party may choose one major party’s ballot at the primary election without changing their registration, allowing unaffiliated voters to participate in a party primary by selecting a ballot.
North Carolina	Open to Unaffiliated	Semi Open	Open to Unaffiliated	Unaffiliated voters may choose and vote in one party’s primary by stating their preference at the polling place.
Rhode Island	Open to Unaffiliated	Semi Open	Open to Unaffiliated	All unaffiliated voters choose one party's ballot to cast their vote in the primary. This choice is viewed as a party declaration.
Nebraska	Nonpartisan/Open	Semi Open	Partially Closed	Registered voters receive ballots based on party affiliation, where party-affiliated voters get their party’s primary ballot and unaffiliated voters receive only nonpartisan ballots unless specific exceptions apply.
Alabama	Open	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	Open	Open	Arkansas state law gives parties discretion to determine participation rules. Both the Democratic and Republican parties operate an open primary.
Georgia	Open	Open	Open	No partisan registration, and voters are bound to their party if there is a runoff
Hawaii	Open	Open	Closed	Voters may receive ballots for all parties without declaring a party preference, but they may cast votes for candidates of only one party (or the nonpartisan ballot) in the primary election.
Michigan	Open	Open	Open	Michigan voters do not declare affiliation but must choose a party's ballot to vote on.
Minnesota	Open	Open	Open	No partisan registration, voters may select one primary to vote in
Mississippi	Open	Open	Open	Mississippi voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Missouri	Open	Open	Open	Missouri voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Montana	Open	Open	Open	Montana voters do not declare affiliation, but they do have to choose a party's ballot to vote.
North Dakota	Open	Open	Differs by Party	All voters receive a single primary ballot with party sections, and they may choose candidates from only one party section, with votes for multiple parties resulting in rejection of the ballot.
South Carolina	Open	Open	Open	South Carolina voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Texas	Open	Open	Open	State does not have party registration.
Vermont	Open	Open	Open	Vermont voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Virginia	Open	Open	Open	Virginia voters do not declare affiliation, but they do have to choose a party's ballot to vote.
Wisconsin	Open	Open	Open	Wisconsin voters do not have to declare affiliation, but they do have to choose a party's ballot to vote. This choice does not change their affiliation.

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.