As of October 13, 2026, 35 of the 100 U.S. Senate seats are on the November 3, 2026 ballot: the 33 regular Class II seats plus special elections in Ohio and Florida [1][2]. Republicans hold 22 of the 35 seats and Democrats hold 13, and 13 seats have no incumbent on the ballot [2]. At the last election for each seat, three were decided by less than 2 points: Georgia (Democrats by 1.2 points in the 2021 runoff), Michigan (Democrats by 1.7) and North Carolina (Republicans by 1.7) [1][7].
Which Senate seats are up in 2026?
Senators serve six-year terms, and the chamber is split into three classes so that about a third of seats is up every two years. The 33 Class II seats last held regular elections in 2020, and their winners' terms end on January 3, 2027 [2]. Of those 33, Republicans hold 20 and Democrats hold 13 [2].
Two more seats are up in special elections because the senators elected in 2022 left the Senate in January 2025: J.D. Vance of Ohio became vice president and Marco Rubio of Florida became secretary of state [2][13]. Their appointed successors, Jon Husted in Ohio and Ashley Moody in Florida, are on the ballot, and the winners will serve the rest of those terms, through January 2029 [2][13]. Ballotpedia lists no other Senate special elections for the 119th Congress [3].
Two Class II seats changed hands by appointment during 2026. In Oklahoma, Gov. Kevin Stitt appointed Alan Armstrong (R) on March 24, 2026, to replace Markwayne Mullin, and Armstrong is not running for a full term [6]. In South Carolina, Sen. Lindsey Graham (R) died on July 11, 2026, and Gov. Henry McMaster appointed his sister, Darline Graham (R), who was sworn in on July 14 [4][5]. Because both seats were already up in 2026, the November 3 elections are the regular elections for full six-year terms, not extra special elections [2][5].
Every 2026 Senate seat and its last result
The table lists each seat, who holds it as of October 13, 2026, whether an incumbent is on the ballot, and the margin at the last election for that seat. The margin is the winner's vote share minus the runner-up's share, in percentage points: R+3.0 means the Republican won by 3.0 points, D+3.0 means the Democrat won by 3.0 points.
| State | Held by (October 13, 2026) | 2026 status | Last result |
|---|---|---|---|
| Alabama | Tommy Tuberville (R) | Open: running for governor | R+20.4 (2020) |
| Alaska | Dan Sullivan (R) | Incumbent running | R+12.7 (2020) |
| Arkansas | Tom Cotton (R) | Incumbent running | R+33.1 (2020, over a Libertarian) |
| Colorado | John Hickenlooper (D) | Incumbent running | D+9.3 (2020) |
| Delaware | Chris Coons (D) | Incumbent running | D+21.5 (2020) |
| Florida (special) | Ashley Moody (R), appointed 2025 | Appointee running | R+16.4 (2022) |
| Georgia | Jon Ossoff (D) | Incumbent running | D+1.2 (2021 runoff) |
| Idaho | Jim Risch (R) | Incumbent running | R+29.4 (2020) |
| Illinois | Dick Durbin (D) | Open: retiring | D+16.1 (2020) |
| Iowa | Joni Ernst (R) | Open: retiring | R+6.6 (2020) |
| Kansas | Roger Marshall (R) | Incumbent running | R+11.4 (2020) |
| Kentucky | Mitch McConnell (R) | Open: retiring | R+19.5 (2020) |
| Louisiana | Bill Cassidy (R) | Open: lost primary | R+40.3 (2020, all-party ballot) |
| Maine | Susan Collins (R) | Incumbent running | R+8.6 (2020) |
| Massachusetts | Ed Markey (D) | Incumbent running | D+33.1 (2020) |
| Michigan | Gary Peters (D) | Open: retiring | D+1.7 (2020) |
| Minnesota | Tina Smith (D) | Open: retiring | D+5.2 (2020) |
| Mississippi | Cindy Hyde-Smith (R) | Incumbent running | R+10.0 (2020) |
| Montana | Steve Daines (R) | Open: retiring | R+10.0 (2020) |
| Nebraska | Pete Ricketts (R) | Incumbent running | R+25.2 (2024 special) |
| New Hampshire | Jeanne Shaheen (D) | Open: retiring | D+15.6 (2020) |
| New Jersey | Cory Booker (D) | Incumbent running | D+16.3 (2020) |
| New Mexico | Ben Ray Luján (D) | Incumbent running | D+6.1 (2020) |
| North Carolina | Thom Tillis (R) | Open: retiring | R+1.7 (2020) |
| Ohio (special) | Jon Husted (R), appointed 2025 | Appointee running | R+6.1 (2022) |
| Oklahoma | Alan Armstrong (R), appointed 2026 | Open: appointee not running | R+26.5 (2022 special) |
| Oregon | Jeff Merkley (D) | Incumbent running | D+17.6 (2020) |
| Rhode Island | Jack Reed (D) | Incumbent running | D+33.1 (2020) |
| South Carolina | Darline Graham (R), appointed 2026 | Appointee running | R+10.3 (2020) |
| South Dakota | Mike Rounds (R) | Incumbent running | R+31.5 (2020) |
| Tennessee | Bill Hagerty (R) | Incumbent running | R+27.0 (2020) |
| Texas | John Cornyn (R) | Open: lost primary runoff | R+9.6 (2020) |
| Virginia | Mark Warner (D) | Incumbent running | D+12.1 (2020) |
| West Virginia | Shelley Moore Capito (R) | Incumbent running | R+43.3 (2020) |
| Wyoming | Cynthia Lummis (R) | Open: retiring | R+46.1 (2020) |
Source: DataPorium Election Results, certified 2020, 2022 and 2024 Senate results [1][9][10][11][12]; Georgia 2021 runoff from the certified results [7]; incumbents and status from Ballotpedia as of October 13, 2026 [2][4][6]. In Arkansas no Democrat was on the 2020 ballot, so the margin is over the Libertarian runner-up; in Louisiana all candidates ran on one ballot in 2020, and the margin is over the leading Democrat [1].
Notes on the special cases
Georgia's seat went to a runoff because no candidate reached 50% on November 3, 2020, when David Perdue (R) led Jon Ossoff (D) by 1.8 points [8]. In the January 5, 2021 runoff, Ossoff received 2,269,923 votes (50.6%) to Perdue's 2,214,979 (49.4%), a margin of 1.2 points [7]. Nebraska's seat was last on the ballot in a 2024 special election, which Pete Ricketts won by 25.2 points [11]. Oklahoma's seat was last on the ballot in a 2022 special election, which Mullin won by 26.5 points [12]. For the Ohio and Florida specials, the last result is the 2022 regular election: Vance won Ohio by 6.1 points and Rubio won Florida by 16.4 points [9][10].
Which seats are open in 2026?
Thirteen of the 35 seats have no incumbent on the November ballot, four held by Democrats and nine by Republicans [2]:
- Retiring (10): Dick Durbin of Illinois, Jeanne Shaheen of New Hampshire, Tina Smith of Minnesota and Gary Peters of Michigan (all Democrats), and Mitch McConnell of Kentucky, Thom Tillis of North Carolina, Joni Ernst of Iowa, Cynthia Lummis of Wyoming, Steve Daines of Montana and appointee Alan Armstrong of Oklahoma (all Republicans) [2].
- Running for another office (1): Tommy Tuberville (R) is running for governor of Alabama [2].
- Lost a primary (2): Bill Cassidy (R) lost the Louisiana Republican primary, and John Cornyn (R) lost the Texas Republican primary runoff [2].
The other 22 seats have an incumbent on the ballot, nine Democrats and 13 Republicans [2]. Three of those 13 Republicans are appointees running for the first time for the seat they hold: Darline Graham of South Carolina, Jon Husted of Ohio and Ashley Moody of Florida [2][3].
What does each party need for a Senate majority?
As of October 13, 2026, the Senate has 53 Republicans, 45 Democrats and two independents who caucus with the Democrats, with no vacancies [2]. A majority is 51 seats. In a 50-50 Senate the vice president, currently J.D. Vance (R), can cast tie-breaking votes [14].
The arithmetic follows from the seats not on the ballot. Republicans hold 31 seats that are not up in 2026 (53 minus 22), and Democrats and the two independents hold 34 (47 minus 13) [2]. That means:
- Republicans reach 51 seats by winning 20 of the 35 races, and 50 seats by winning 19.
- Democrats and their two allied independents reach 51 seats by winning 17 of the 35 races, a net gain of four seats.
Ballotpedia describes the same math as Democrats needing a net gain of four seats, and Republicans being able to lose a net two seats and keep control, with the vice president breaking a 50-50 tie [2].
How close were the last races for these seats?
DataPorium data show a wide range of margins across the 35 seats. Three were last decided by under 2 points (Georgia, Michigan and North Carolina) [1][7]. Seven more were decided by under 10 points: Minnesota (D+5.2), New Mexico (D+6.1), Ohio's special seat (R+6.1), Iowa (R+6.6), Maine (R+8.6), Colorado (D+9.3) and Texas (R+9.6) [1][9]. Seven were decided by more than 30 points, led by Wyoming (R+46.1) and West Virginia (R+43.3) [1].
A past margin describes the last election for that seat, often with a different candidate. In 12 of the 13 open seats, the last result was a 2020 race won by the senator who is now leaving; the exception is Oklahoma, where the last winner, Mullin, resigned in March 2026 [1][2][6].
On November 3, 2026, voters fill 35 Senate seats, 22 held by Republicans and 13 by Democrats, and 13 of them have no incumbent on the ballot.
Frequently asked questions
How many Senate seats are up in 2026?
Thirty-five: the 33 regular Class II seats and two special elections, in Ohio and Florida, for terms that end in January 2029 [2][3].
How many Senate seats does each party have to defend in 2026?
Republicans hold 22 of the 35 seats on the ballot (20 regular and both specials) and Democrats hold 13 [2].
Which senators are not running for re-election in 2026?
Eleven: Durbin, Shaheen, Smith and Peters (Democrats) and McConnell, Tillis, Ernst, Lummis, Daines, Armstrong and Tuberville (Republicans); Cassidy and Cornyn ran but lost their primaries [2].
How many seats do Democrats need to win the Senate in 2026?
Democrats and the two independents who caucus with them need a net gain of four seats, which means winning 17 of the 35 races to reach 51 [2].
Sources & References
- [1] DataPorium Election Results (2020 US Senate results by state)
- [2] Ballotpedia, United States Senate elections, 2026 (accessed October 13, 2026)
- [3] Ballotpedia, Special elections to the 119th United States Congress (2025-2026) (accessed October 13, 2026)
- [4] NPR, Darline Graham, the sister of Lindsey Graham, is sworn in to serve out his term (July 14, 2026)
- [5] Ballotpedia News, Lindsey Graham's death will set off a special primary election (July 16, 2026)
- [6] Ballotpedia, Alan Armstrong (accessed October 13, 2026)
- [7] Ballotpedia, United States Senate runoff elections in Georgia (January 5, 2021), certified results
- [8] DataPorium Election Results (2020 US Senate, Georgia)
- [9] DataPorium Election Results (2022 US Senate, Ohio)
- [10] DataPorium Election Results (2022 US Senate, Florida)
- [11] DataPorium Election Results (2024 US Senate special election, Nebraska)
- [12] DataPorium Election Results (2022 US Senate special election, Oklahoma)
- [13] Ballotpedia, United States Senate special election in Florida, 2026 (accessed October 13, 2026)
- [14] National Archives, The Constitution of the United States: A Transcription (Article I, Section 3)
