A House seat that opens up is always filled by a special election. No one can be appointed to the House. A Senate seat is usually filled first by the governor’s temporary appointee, who serves until voters choose a replacement in a special election. All but four states allow those appointments, and several require the governor to pick someone from the departing senator’s party.
The difference comes straight from the Constitution, and in a closely divided Congress it can change the math on major votes for months.
How is a House vacancy filled? #
Article I, Section 2 says that when a House seat becomes vacant, the state’s governor “shall issue Writs of Election to fill such Vacancies.” The Framers wanted every representative to be directly elected, so there’s no such thing as an appointed House member.
The Constitution sets no deadline, so timing is up to state law and often the governor:
- Some states set a window, requiring a special election within a certain number of days.
- Many governors consolidate the special election with an already scheduled election to save money and raise turnout.
- Near the end of a term, some states let a seat stay empty until the regular November election.
The gap can be long. Rep. Sylvester Turner of Texas died in March 2025. Governor Greg Abbott scheduled the special election for November 4, 2025, the state’s regular election date, and it went to a runoff on January 31, 2026, which Christian Menefee won. The district had no representative for about ten months.
While a House seat is empty, the number of votes needed for a majority drops, because a majority is counted among members currently serving. With a narrow margin, a few vacancies can decide whether the majority party can pass a bill on its own.
How is a Senate vacancy filled? #
The 17th Amendment, ratified in 1913, made senators directly elected and set the vacancy rule. The governor must call a special election, but the state legislature can let the governor make a temporary appointment until that election happens. Nearly every state allows it.
| Approach | How it works | States |
|---|---|---|
| Governor appoints freely | Appointee serves until a special election, often at the next regular November election | Most states |
| Governor appoints from the same party | The appointee must share the departing senator’s party; in some states the party submits a short list | Several states, including Arizona, Hawaii, North Carolina, Utah and Wyoming |
| No appointment; special election only | The seat stays empty until voters fill it | Kentucky, North Dakota, Rhode Island and Wisconsin |
States also differ on how quickly the special election must happen. In many, the appointee serves until the next statewide general election, which can be nearly two years away. Others require a faster special election and let the appointee serve only in the meantime. Because these laws change, especially when a vacancy looks likely, check your state’s current statute before assuming which rule applies.
Whoever wins the special election serves only the rest of the original six-year term. The seat then goes back on its regular schedule, which is set by its Senate class. Our explainer on Senate classes covers how that rotation works.
Which Senate seats have special elections in 2026? #
Two. Both opened when senators joined the Trump administration in January 2025:
- Ohio. JD Vance resigned to become vice president. Governor Mike DeWine appointed Jon Husted, the lieutenant governor.
- Florida. Marco Rubio resigned to become secretary of state. Governor Ron DeSantis appointed Ashley Moody, the state attorney general.
Both appointees are on the ballot on November 3, 2026, and the winners will serve until those terms end in January 2029. Add the 33 regularly scheduled seats and 35 Senate seats are up this year. Our guide to which Senate seats are up in 2026 lists every race.
House vs. Senate vacancies at a glance #
| House | Senate | |
|---|---|---|
| Constitutional basis | Article I, Section 2 | 17th Amendment |
| Can the governor appoint? | Never | Yes, in all but four states |
| How the seat is permanently filled | Special election | Special election |
| Seat empty until election? | Yes | Usually no, if an appointment is made |
| Winner serves | Rest of the two-year term | Rest of the six-year term |
Why do vacancies matter so much? #
Majorities are thin. When a party has only a few seats to spare, one death or resignation can decide whether it can pass a bill, confirm a nominee or clear a procedural vote without help from the other side.
Appointments can flip a seat. In a state that allows free appointments, a governor of one party can replace a senator of the other, instantly changing the Senate’s balance until the special election. That possibility is why some states adopted same-party requirements.
Special elections are early signals. They’re closely watched as tests of the national mood, though turnout is usually low and the results don’t always carry over to November.
Committees shift. Committee seats are divided by party ratio, so a vacancy can change a committee’s balance on a key vote.
How do you follow special elections? #
Special elections held on November 3 appear on the regular ballot, and pollsters cover the high-profile ones like any other Senate race. Election Tracker groups every published Senate poll by race, including special elections when pollsters cover them, with each poll’s pollster, sample size and dates and a 30-day average once there’s enough polling. You can pin the races you care about to the top. It’s free on iPhone. For the rest of this year’s dates, see our 2026 midterm calendar.
Frequently asked questions #
What happens when a senator dies or resigns? #
In most states the governor appoints a temporary replacement, who serves until a special election. In Kentucky, North Dakota, Rhode Island and Wisconsin, the seat stays empty until voters fill it. The special election winner serves the rest of the original term.
Can a governor appoint someone to the House? #
No. The Constitution requires every House vacancy to be filled by election. The seat stays empty until the special election is held and the winner is sworn in.
How long does it take to fill a House seat? #
It depends on state law and the governor’s scheduling. Some vacancies are filled within two or three months; others take most of a year, especially when the special election is combined with a regular election or goes to a runoff.
Can a governor appoint a senator from the other party? #
In states without a same-party rule, yes. Several states require the appointee to belong to the departing senator’s party, and some have the party submit names for the governor to choose from.
What is a writ of election? #
It’s the formal order a governor issues to call a special election for a vacant seat. For the House, the Constitution specifically assigns this job to the state’s executive authority.