NCSL - National Conference of State Legislatures

12/15/2025 | Press release | Distributed by Public on 12/15/2025 12:13

State Primary Election Types

Related Topic: Elections

The laws governing state primaries are complex and nuanced, and state primary laws have been a cause of confusion among voters and election administrators alike. The manner in which party primary elections are conducted varies widely by state. Primaries can be categorized as closed,  partially closed,  partially open, open to unaffiliated voters,  open or  multi-party. For a list of all 50 states and their primary types, please see the table State Primary Types at the bottom of the page.

States often use different systems for how they conduct their state and presidential primaries: Some states hold their state and presidential primaries on the same day, some hold them weeks or even months apart, and some hold the two primaries on the same day but have different rules for each. See NCSL's How States Differentiate Presidential Primaries From State Primaries for which state primary rules differ from presidential elections.

For more information on primary elections see the report Primaries: More Than One Way to Find a Party Nominee. 

Closed Primaries

In general, a voter seeking to vote in a closed primary must be a registered party member. Typically, the voter affiliates with a party on their voter registration application. In states without partisan voter registration, voters who are not bona fide members of the party may face penalties. Independent or unaffiliated voters, by definition, are excluded from participating in the party nomination contests. This system deters "cross-over" voting by members of other parties and generally contributes to a strong party organization.

Partially Closed

In this system, state law permits political parties to choose whether to allow unaffiliated voters or voters not registered with the party to participate in their nominating contests before each election cycle. In this system, parties may allow unaffiliated voters, while still excluding members of opposing parties. This system gives the parties more flexibility from year to year about which voters to include. At the same time, it can create uncertainty about whether certain voters can participate in party primaries in a given year. 

Partially Open

This system permits voters to cross party lines, but their ballot choice may be regarded as a form of registration with the corresponding party. Iowa, for instance, asks voters to choose a party on the state voter registration form, yet it allows a primary voter to publicly change party affiliation for purposes of voting in a primary election. Some state parties keep track of who votes in their primaries as a means of identifying their backers.

Open to Unaffiliated Voters

Many states allow unaffiliated voters to participate in any party primary they choose, but do not allow voters who are registered with one party to vote in another party's primary. This system differs from a true open primary because a Democrat cannot cross over and vote in a Republican party primary, or vice versa. New Hampshire requires that unaffiliated voters declare affiliation with a party at the polls in order to vote in that party's primary. In Colorado, unaffiliated voters who vote by mail must return just one party's mail ballot, or state which party ballot they want at the polls. The choice is public information, although it does not change the voter's unaffiliated status.

Open Primaries

In general, but not always, states that do not ask voters to choose parties on the voter registration form are "open primary" states. In an open primary, voters choose which party's ballot to vote, but this decision is private and does not register the voter with that party. This permits a voter to cast a vote across party lines in a primary election. Critics argue that an open primary dilutes the parties' ability to nominate. Supporters say this system gives voters maximal flexibility-allowing them to cross party lines-and maintains their privacy. 

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Multi-Party Primaries (Including Top-Two and Similar Systems)

A small but growing number of states hold a single primary in which all candidates, regardless of party, are listed on a single ballot. States vary in the number of candidates who advance out of this primary to the general election. For example, California and Washington use a "top-two" primary format in which each candidate lists his or her party affiliation or, in Washington's case, a party "preference." The top two vote-getters in each race, regardless of party, advance to the general election.

Elections for Nebraska's unicameral, nonpartisan legislature closely mirror this process except ballots do not identify the candidates' party. (Nebraska uses open primaries for other state offices.) Alaska uses a similar system except four candidates advance to the general election instead of two.

Advocates of the "top-two" format argue that it increases the likelihood of moderate candidates advancing to the general election ballot. Opponents maintain it reduces voter choice by making it possible that two candidates of the same party face off in the general election. They also contend it is tilted against minor parties who will face slim odds of earning a spot on the general election ballot.

State legislative and some statewide elections in Louisiana use a modified version of this system called an "all-comers" primary; other organizations may refer to this as a "jungle" primary. In these elections, on the general election date, all candidates run on the same ticket. If no candidate receives over 50% of the vote, then the top two vote-getters face a runoff six weeks later. One way to look at this is to say there is no primary election-just a general election for all candidates, with a runoff when needed. Congressional and other offices are run through open primaries.

State

Statute

Primary Type

Alaska

Alaska Stat. § 15.25.010

Top-Four

California

Cal. Election Code § 2151
Cal. Election Code § 9083.5

Top-Two

Louisiana

La. Rev. Stat. Ann. § 18:401
La. Rev. Stat. Ann. § 18:511

All-Comers

Nebraska

Neb. Rev. Stat. § 32-912

Nonpartisan/Open

Washington

Wash. Rev. Code § 29A.52.112

Top-Two

State Primary Types

State

Statute

Primary Type

Alabama

Ala. Code § 17-3-30 et seq.

Open

Alaska

Alaska Stat. § 15.25.010

Top-Four

Arizona

Ariz. Rev. Stat. Ann. § 16-467

Open to Unaffiliated

Arkansas

Ark. Stat. Ann. § 7-7-307
Ark. Stat. Ann. § 7-7-308

Open

California

Cal. Election Code § 2151
Cal. Election Code § 9083.5

Top-Two

Colorado

Colo. Rev. Stat. § 1-7-201

Open to Unaffiliated

Connecticut

Conn. Gen. Stat. § 9-431

Partially Closed

Delaware

Del. Code Ann. tit. 15, § 3110

Closed

Florida

Fla. Stat. § 101.021

Closed

Georgia

Ga. Code § 21-2-224

Open

Hawaii

Hawaii Rev. Stat. § 12-31

Open

Idaho

Idaho Code § 34-904
Idaho Code § 34-904A

Partially Closed

Illinois

Ill. Rev. Stat. ch. 10, § 5/7-44

Partially Open

Indiana

Ind. Code § 3-10-1-6

Partially Open

Iowa

Iowa Code § 43.42

Partially Open

Kansas

Kan. Stat. Ann. § 25-3301

Partially Closed

Kentucky

Ky. Rev. Stat. § 116.055

Closed

Louisiana

La. Rev. Stat. Ann. § 18:401
La. Rev. Stat. Ann. § 18:511

All-Comers/Open to Unaffiliated**

Maine

Me. Rev. Stat. Ann. tit. 21-A, § 340

Open to Unaffiliated

Maryland

Md. Election Code Ann. § 8-202

Partially Closed*

Massachusetts

Mass. Gen. Laws Ann. ch. 53, § 38
Mass. Gen. Laws Ann. ch. 53, § 37

Open to Unaffiliated

Michigan

Mich. Comp. Laws § 168.531

Open

Minnesota

Minn. Stat. § 204D.08

Open

Mississippi

Miss. Code Ann. § 23-15-575

Open

Missouri

Mo. Rev. Stat. § 115.397

Open

Montana

Mont. Code Ann. § 13-10-301

Open

Nebraska

Neb. Rev. Stat. § 32-912

Nonpartisan/Open***

Nevada

Nev. Rev. Stat. § 293.287

Partially Open

New Hampshire

N.H. Rev. Stat. Ann. § 659:14

Open to Unaffiliated

New Jersey

N.J. Rev. Stat. § 19:23-45

Closed

New Mexico

N.M. Stat. Ann. § 1-4-15

Open

New York

N.Y. Election Law § 17-102

Closed

North Carolina

N.C. Gen. Stat. § 163-59
N.C. Gen. Stat. § 163-119

Open to Unaffiliated

North Dakota

N.D. Cent. Code § 16.1-11-22

Open

Ohio

Ohio Rev. Code Ann. § 3513.19

Partially Open

Oklahoma

Okla. Stat. tit. 26, § 1-104

Partially Closed

Oregon

Or. Rev. Stat. § 254.365

Partially Closed*

Pennsylvania

Pa. Stat. tit. 25, § 299

Closed

Rhode Island

R.I. Gen. Laws § 17-15-24

Open to Unaffiliated

South Carolina

S.C. Code Ann. § 7-9-20

Open

South Dakota

S.D. Codified Laws Ann. § 12-6-26

Partially Closed

Tennessee

Tenn. Code Ann. § 2-7-115

Closed

Texas

Tex. Election Code Ann. § 172.086

Open

Utah

Utah Code Ann. § 20A-9-403

Partially Closed

Vermont

Vt. Stat. Ann. tit. 17, § 2363

Open

Virginia

Va. Code § 24.2-530

Open

Washington

Wash. Rev. Code § 29A.52.112

Top-Two

West Virginia

W. Va. Code § 3-4A-20

Partially Closed

Wisconsin

Wis. Stat. § 5.62

Open

Wyoming

Wyo. Stat. § 22-5-214
Wyo. Stat. § 22-5-212
Wyo. Stat. § 22-5-209

Closed

*Maryland and Oregon use partially closed primaries, but at this time both parties choose to allow only party members to participate.

**Louisiana uses an open to unaffiliated primary system for the following offices: state supreme court justice, State Board of Elementary and Secondary Education, and the Public Service Commission. It uses an all-comers primary system for all other state offices, including state representatives and senators.

***Nebraska's unicameral legislature uses nonpartisan elections that closely resemble a top-two primary system. It uses open primaries for all other state offices.

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Note: This page should be used for general informational purposes only.

Our organization does not run elections and cannot provide legal advice. If you are a voter looking for assistance, please contact your local election official. You can find your local election official's website and contact information by using this database from the US Vote Foundation.

NCSL - National Conference of State Legislatures published this content on December 15, 2025, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on December 15, 2025 at 18:13 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]