2026 voter guide

Open primaries, explained for every voter

Last updated: November 2026

Open primaries are primary elections where any registered voter can choose a party ballot without first joining that party.

Open Primary Guide counts 20 states with fully open primaries in 2026, three with semi-open rules, and three that give every voter one nonpartisan ballot. In the 15 closed-primary states, about 66.3 million registered voters live under rules that keep independents out of party primaries.

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What are open primaries?

An open primary lets you walk in, ask for one party's ballot, and vote, with no party membership required. Your registration stays the same, and in most fully open states your ballot choice is not treated as joining a party.

That is different from a closed primary, where only registered party members get a ballot, and from a nonpartisan primary, where every candidate appears on one shared ballot. Primaries matter because they often decide the race: in 2024, 87% of congressional races were effectively settled in the primary, according to the Unite America Institute.

Definition

Open primary definition

An open primary is a party primary election in which any registered voter may take part in one party's contest without being a registered member of that party. Voters choose which party ballot to use at the polls or when requesting a mail ballot, and can vote in only one party primary per election.

Close relatives include the semi-open primary, where the ballot choice may be recorded, and the semi-closed primary, where only unaffiliated voters may choose. Read the full open primary definition.

Numbers

Open primaries by the numbers

26 states let every registered voter cast a primary ballot without joining a party (20 open, 3 semi-open, 3 nonpartisan).
87% of 2024 congressional races were effectively decided in the primary, per the Unite America Institute.
63 million Americans, 28.9% of registered voters, are registered independent, per Independent Voter Project state data.
18.2 million independents across 15 closed states have no party primary ballot.

See every primary statistic with sources.

Open vs closed primaries at a glance

The single question that separates every primary system is who gets a ballot. This table runs from the most open systems to the most restrictive. For the full side-by-side, see open vs closed primaries.

Open Primary Guide: the six U.S. primary types in 2026, from most open to least open.
Primary type	Who can vote	Must join a party?	Independents	States (2026)
Top-Two	Every registered voter	No	Same single ballot as everyone	2
Top-Four	Every registered voter	No	Same single ballot as everyone	1
Open	Any registered voter	No	Vote in any one party primary	20
Semi-Open	Any registered voter	No, but the ballot choice may be recorded	Request any party ballot	3
Semi-Closed	Party members plus unaffiliated voters	Only if registered with another party	Pick one party ballot	10
Closed	Registered party members only	Yes, before the deadline	No primary ballot	15

Which states have open primaries in 2026?

The 20 states with fully open primaries in 2026 are Alabama, Arkansas, Georgia, Hawaii, Illinois, Indiana, Michigan, Minnesota, Mississippi, Missouri, Montana, New Mexico, North Dakota, Ohio, South Carolina, Tennessee, Texas, Vermont, Virginia, and Wisconsin. Arizona, Colorado, and Maine use semi-open primaries, and California and Washington use top-two primaries, while Alaska uses a top-four system.

The 15 closed-primary states are Connecticut, Delaware, Florida, Iowa, Kansas, Kentucky, Louisiana, Maryland, Nevada, New Jersey, New York, Oregon, Pennsylvania, South Dakota, and Wyoming. Search the full 2026 state list to find your state and its rules.

Step by step

How to vote in your state's primary

Look up your state's primary type in the 2026 state list.
Confirm you are registered at vote.gov, which links to every official state registration page.
In a closed or semi-closed state, check the party affiliation deadline. It can fall months early: New York's was February 14 for its June 23, 2026 primary.
Find your primary date and your polling place or mail ballot request deadline on your state election office website.
On primary day, ask for the ballot you want (open states) or the one for your party (closed states), and vote.

Explore the guide

23.3%

National primary turnout in the 2026 midterm cycle, still rising in midterm years.

Source: Bipartisan Policy Center

Share of voting-age Americans who cast ballots in the primaries that decided 2024 congressional races.

Source: Unite America Institute

22.1%

Share of all possible 2026 primaries that were actually contested.

Source: Ballotpedia

Start with open primaries

The first step is supporting open primaries for every voter. Next, see how More Choice Voting builds on them.

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Common questions

See all 44 answers

What are open primaries?

Open primaries are primary elections where any registered voter can choose one party ballot without first joining that party. You decide which primary to vote in on election day or when you request a mail ballot. In 2026, 20 states use fully open primaries.

How many states have open primaries?

Twenty states have fully open primaries in 2026. Counting semi-open states (3) and nonpartisan single-ballot states (3), 26 states let every registered voter cast a primary ballot without joining a party. Classifications differ between sources, so a count you see elsewhere may be slightly higher or lower depending on how semi-open states are labeled.

What is the difference between open and closed primaries?

The difference is who may vote. Open primaries let any registered voter choose one party ballot, while closed primaries limit each party primary to that party's registered members. In practice, independents can vote in every open primary state and in none of the 15 closed primary states.

Can independents vote in primary elections?

It depends on the state. Independents can vote in open, semi-open, and nonpartisan primary states, and they can pick a party ballot in most semi-closed states. In the 15 closed primary states they cannot vote in party primaries at all unless they first register with a party before the deadline.

Which states have top-two primaries?

California and Washington are the two states with top-two primaries in 2026. Washington adopted its system in 2004 and California in 2010 through Proposition 14. In both, every candidate appears on one ballot, every voter takes part, and the two highest vote-getters advance to November regardless of party.

Why do parties prefer closed primaries to open primaries?

Parties prefer closed primaries because they keep nominee selection with registered members. That protects against crossover voting, rewards loyal members, and gives parties a clear list of supporters. Parties also cite their First Amendment freedom of association, which the Supreme Court relied on in California Democratic Party v. Jones (2000).

How can I support open primaries?

The simplest first step is to add your name to an open primaries petition, which takes about 30 seconds. The Independent Voter Project runs a national open primaries petition and lists ways to sign, donate, or subscribe on its take-action page. After that, explore More Choice Voting, which builds on open primaries.