2026 Congressional Primary Elections: Calendar, Rules & Key Dates

What Is a Congressional Primary?

A congressional primary is an election used to choose each party's nominee for the U.S. House or Senate in the November general election. Primaries narrow the field: voters pick a Democrat, a Republican, and occasionally a third-party nominee, who then face off in the general election.

Primary rules are set by each state, not Congress, so the date, who can vote, and how ties are resolved all vary by state.

Types of Primary Elections

2026 Primary Dates by State

2026 congressional primaries span about seven months, from early March through mid-September. Click any state for full details, voter eligibility rules, and a live countdown.

Sources: NCSL, Ballotpedia, FEC. Primary dates are set by each state and may change — always verify with your state's election office.

What's on the 2026 Primary Ballot

• All 435 U.S. House seats — every Representative is up every 2 years.
• 33 U.S. Senate seats (Class II) — these senators were last elected in 2020 and are finishing 6-year terms. See the Senate class schedule.
• 36 governorships and many state legislative seats — not federal, but usually on the same ballot.
• Ballot initiatives and local races, which vary by state.

Because it's a midterm year, there is no presidential primary in 2026. The next presidential primaries are in 2028.

How Primaries Differ from the General Election

Primary vs. Caucus

Most states use primaries — a standard secret-ballot election. A few states still use caucuses, where party members gather in person, discuss candidates, and express preferences through raised hands, sign-in sheets, or preference groups.

In 2026, congressional caucuses are rare; the caucus format is more common in presidential years and has been phased out in most states.

Voter Registration Deadlines

Every state sets its own voter registration deadline for primaries. Deadlines typically fall between 15 and 30 days before the primary, though a growing number of states offer same-day voter registration.

In closed-primary states, you may also need to register with a specific party well in advance. Check vote.gov or your state board of elections for exact deadlines.

After the Primary: Path to November

Once all primaries conclude in September, nominees campaign through October. Early voting begins in most states in mid-to-late October, and mail-in ballots are accepted on varying schedules. Election Day is Tuesday, November 3, 2026. The winners are sworn in on January 3, 2027 as the 120th Congress begins.

See our full 2026 election timeline for key dates from campaign season through Inauguration.

See Who's Up for Election

Browse the 2026 elections page to see every Senator and Representative on the ballot, or use the interactive map to find who represents your state.