In the United States, voter eligibility is determined by a combination of state rules and federal protections. States set many of the specific requirements for voting, including registration processes, deadlines, and identification rules, but these must follow constitutional limits and federal law. This creates a system where all states follow the same basic framework, while still allowing differences in how elections are carried out.
In general, individuals can vote in federal, state, and local elections if they are U.S. citizens, including naturalized citizens, are at least 18 years old on or before Election Day, and meet their state’s residency requirements, meaning they live in the state where they are voting. Most states also require voters to register before an election, although the process varies. Some states allow registration online, by mail, or in person, and deadlines differ depending on state law. Non-citizens are not legally allowed to vote in federal and state elections.
Federal laws have expanded access to voter registration and helped standardize parts of the process. The National Voter Registration Act of 1993 (NVRA) requires states to offer multiple ways to register, including at motor vehicle offices, by mail, and at public assistance agencies. Often called the “Motor Voter” law, it allows individuals to register or update their information when applying for or renewing a driver’s license. The law also requires states to maintain voter registration lists and set rules for how those lists are updated and kept accurate.
Although states have the authority to set additional rules, those rules must comply with constitutional protections, such as the 19th Amendment, which prohibits denying the right to vote on the basis of sex. States may set different requirements for voter identification, such as requiring a government-issued ID or allowing alternative forms of identification. They also set registration deadlines, with some requiring registration weeks before an election and others allowing same-day registration.
States also differ in how they allow people to cast their ballots. Many states offer early voting, allowing voters to vote before Election Day, while others provide more limited options. Most states allow some form of absentee or mail-in voting, though the rules for requesting and submitting these ballots vary. In addition, some states restrict voting for individuals with felony convictions, either while they are incarcerated or until certain conditions are met after release, while others restore voting rights more quickly. These differences affect how voters participate in elections across the United States.