Eligible citizens in every state have the right to vote. But how that happens differs based on where they live. States set many of the rules for registration, in-person voting, mail ballots, recounts, audits, and primaries. Federal law provides some nationwide requirements, but there is no single American election system. State and local governments determine much of how elections work.
How does voter registration differ by state?
Voter registration works differently depending on where you live, and a few states show just how wide that range can be.
North Dakota stands apart because it is the only state without voter registration. Lawmakers repealed the state's registration requirement in 1951. Instead, voters establish their eligibility when they show up to vote.
Among states that do register voters, Mississippi and Colorado have two very different approaches.
Mississippi does not offer online or automatic voter registration or registration on Election Day. Voters generally must register at least 30 days before an election.
Colorado offers more ways to register: voters can register online, the state uses automatic voter registration, and people can preregister beginning at age 15. Eligible voters can also register in person through Election Day.
Across the states:
- Online voter registration: Forty-one states and Washington, DC, allow voters to register online.
- Automatic voter registration: Twenty-four states and Washington, DC, automatically register voters when they receive other services, such as getting a driver’s license.
- Pre-registration before turning 18: Twenty-seven states and Washington, DC, allow pre-registration, including some starting at age 16.
- Same-day registration in all elections: Twenty-one states and Washington, DC, allow voters to register on Election Day before casting their ballots.
How does in-person voting vary by state?
Where and when people can vote in person, and what they need to bring, varies by state. Alabama and California illustrate two versions of these rules.
Alabama requires voter ID, does not use Election Day vote centers, and does not offer general early in-person or no-excuse absentee voting.
California generally does not require ID at the polls, offers early voting and vote centers in participating counties, and mails ballots to all active registered voters.
Across the states:
- Voter ID: Thirty-six states require voters to present identification when voting in person. Other states generally verify voters through other information or require identification only in certain circumstances.
- No-excuse absentee voting: Thirty-six states allow any voter to cast an absentee ballot without providing a reason. In the remaining states, voters generally need to meet certain qualifications to vote absentee.
- Vote centers on Election Day: Twenty-one states and Washington, DC, allow vote centers. Voters can cast a ballot anywhere in their jurisdiction, rather than at one assigned polling place.
- Early in-person voting: Forty-seven states and Washington, DC, allow voters to cast a ballot in person before Election Day without needing an excuse.
How does mail voting vary by state?
States differ not just in who receives a mail ballot, but in how voters can return it and what happens after election officials receive it. California and Arkansas illustrate that range.
California mails ballots to all active registered voters, permits drop boxes, allows voters to fix certain problems with their ballots, and can begin processing mail ballots before Election Day.
Arkansas does not mail ballots to all voters, prohibits drop boxes, does not have a ballot cure process and does not permit electronic ballot return.
California and Arkansas both allow a voter to designate another adult to return a ballot.
Across the states:
- Ballots mailed automatically: Seven states and DC mail ballots to all active registered voters for every election. Vermont does so for general elections.
- Ballot return deadlines: Thirty-five states require mail ballots to be received by Election Day, while 13 and DC accept qualifying ballots after Election Day. Louisiana requires them before Election Day, and Alaska has separate rules.
- Who can return a ballot: Twenty states allow a voter to designate any adult to return a ballot. Seventeen limit that role to people such as family members, household members, or caregivers. Five states generally require the voter to return their own ballot.
- Ballot drop boxes: Twenty-eight states and DC permit ballot drop boxes. Seven prohibit them by statute, five do not permit them, and laws in 10 states do not specify whether they are allowed.
- Ballot cure: Thirty-three states and DC have a process that allows voters to correct certain problems that would otherwise cause a mail ballot to be rejected. Seventeen states do not.
- When processing begins: Seventeen states allow election officials to begin processing mail ballots when they receive them. Seven wait until Election Day. The others begin at different points before Election Day. Processing can include steps such as verifying signatures and preparing ballots; it does not mean votes are being counted.
- Electronic ballot return: Eighteen states do not permit ballots to be returned electronically. The others allow it for at least some voters, most often people covered by the Uniformed and Overseas Citizens Absentee Voting Act (UOCAVA) — a federal law covering members of the uniformed services serving away from home — their eligible family members, and US citizens living abroad.
In what other ways do state elections differ?
States also set different rules for recounting and auditing election results, and for deciding who can participate in primary elections.
- Automatic recounts: Twenty-five states and DC automatically recount certain close races. The other 25 do not. The rules for when a recount is required vary by state.
- Post-election tabulation audits: Forty-seven states and DC use post-election tabulation audits to check a sample of ballots or voting systems against the reported results. Massachusetts has a limited audit process and Maine has a pilot program. Mississippi is the only state without a post-election tabulation audit, although the state does conduct other types of post-election procedural audits. Audit methods and requirements vary by state.
- Primary elections: Twenty-three states use open primaries, where voters can generally choose which party’s primary to participate in regardless of their registration. Eight states and DC use closed primaries, while others use partially open or partially closed systems. For certain offices, Alaska uses a top-four primary, while California and Washington use top-two systems: candidates compete on the same primary ballot, and the leading candidates advance regardless of party.
No two states run elections the same way
Taken together, these rules show why there is no single model for how American elections work. States that take similar approaches in one area can make very different choices in another. A state might allow same-day registration but require voter ID, mail ballots to every voter but restrict who can return them, or offer early voting alongside a different type of primary.
The result is a different combination of rules in every state. The Election Assistance Commission describes US election administration as highly decentralized — state law governs much of how elections are conducted, with additional differences in how elections are run locally.
The map below shows each state’s policies combined into its “election fingerprint.” No two states are exactly the same. Use it to compare a single state’s election system or explore how one rule varies across the country.
