You must be registered with a political party to vote in that party's primary. Independent/unaffiliated voters cannot participate unless they re-register before the deadline.
To vote in the November 3, 2026 general election, register by ≈ October 19, 2026 — 15 days before Election Day. Registering online or by mail is different: mail registrations must be postmarked 15 days before. Iowa also allows same-day registration on Election Day, so missing the deadline does not cost you your vote.
Check your registration status and find your polling place at vote.gov. Deadlines marked ≈ are computed from statute and can shift — see all registration deadlines by state.