| State | Senator | Party | Reelection |
| Alabama | Douglas Jones | Democratic | 2020 |
| Alabama | Richard Shelby | Republican | 2022 |
| Alaska | Dan Sullivan | Republican | 2020 |
| Alaska | Lisa Murkowski | Republican | 2022 |
| Arizona | Jeff Flake | Republican | 2018 |
| Arizona | John McCain | Republican | 2022 |
| Arkansas | John Boozman | Republican | 2022 |
| Arkansas | Tom Cotton | Republican | 2020 |
| California | Dianne Feinstein | Democratic | 2018 |
| California | Kamala Harris | Democratic | 2022 |
| Colorado | Cory Gardner | Republican | 2020 |
| Colorado | Michael Bennet | Democratic | 2022 |
| Connecticut | Christopher Murphy | Democratic | 2018 |
| Connecticut | Richard Blumenthal | Democratic | 2022 |
| Delaware | Christopher Coons | Democratic | 2020 |
| Delaware | Thomas Carper | Democratic | 2018 |
| Florida | Bill Nelson | Democratic | 2018 |
| Florida | Marco Rubio | Republican | 2022 |
| Georgia | David Perdue | Republican | 2020 |
| Georgia | Johnny Isakson | Republican | 2022 |
| Hawaii | Brian Schatz | Democratic | 2022 |
| Hawaii | Mazie Hirono | Democratic | 2018 |
| Idaho | James Risch | Republican | 2020 |
| Idaho | Mike Crapo | Republican | 2022 |
| Illinois | Richard Durbin | Democratic | 2020 |
| Illinois | Tammy Duckworth | Democratic | 2022 |
| Indiana | Joe Donnelly | Democratic | 2018 |
| Indiana | Todd Young | Republican | 2022 |
| Iowa | Chuck Grassley | Republican | 2022 |
| Iowa | Joni Ernst | Republican | 2020 |
| Kansas | Jerry Moran | Republican | 2022 |
| Kansas | Pat Roberts | Republican | 2020 |
| Kentucky | Mitch McConnell | Republican | 2020 |
| Kentucky | Rand Paul | Republican | 2022 |
| Louisiana | Bill Cassidy | Republican | 2020 |
| Louisiana | John Kennedy | Republican | 2022 |
| Maine | Angus King | Independent | 2018 |
| Maine | Susan Collins | Republican | 2020 |
| Maryland | Benjamin Cardin | Democratic | 2018 |
| Maryland | Chris Van Hollen | Democratic | 2022 |
| Massachusetts | Edward Markey | Democratic | 2020 |
| Massachusetts | Elizabeth Warren | Democratic | 2018 |
| Michigan | Debbie Stabenow | Democratic | 2018 |
| Michigan | Gary Peters | Democratic | 2020 |
| Minnesota | Tina Smith | Democratic | 2018 |
| Minnesota | Amy Klobuchar | Democratic | 2018 |
| Mississippi | Roger Wicker | Republican | 2018 |
| Mississippi | Thad Cochran | Republican | 2020 |
| Missouri | Claire McCaskill | Democratic | 2018 |
| Missouri | Roy Blunt | Republican | 2022 |
| Montana | Jon Tester | Democratic | 2018 |
| Montana | Steve Daines | Republican | 2020 |
| Nebraska | Ben Sasse | Republican | 2020 |
| Nebraska | Deb Fischer | Republican | 2018 |
| Nevada | Catherine Cortez Masto | Democratic | 2022 |
| Nevada | Dean Heller | Republican | 2018 |
| New Hampshire | Jeanne Shaheen | Democratic | 2020 |
| New Hampshire | Margaret Wood Hassan | Democratic | 2022 |
| New Jersey | Cory Booker | Democratic | 2020 |
| New Jersey | Robert Menendez | Democratic | 2018 |
| New Mexico | Martin Heinrich | Democratic | 2018 |
| New Mexico | Tom Udall | Democratic | 2020 |
| New York | Charles Schumer | Democratic | 2022 |
| New York | Kirsten Gillibrand | Democratic | 2018 |
| North Carolina | Richard Burr | Republican | 2022 |
| North Carolina | Thom Tillis | Republican | 2020 |
| North Dakota | Heidi Heitkamp | Democratic | 2018 |
| North Dakota | John Hoeven | Republican | 2022 |
| Ohio | Rob Portman | Republican | 2022 |
| Ohio | Sherrod Brown | Democratic | 2018 |
| Oklahoma | James Inhofe | Republican | 2020 |
| Oklahoma | James Lankford | Republican | 2022 |
| Oregon | Jeff Merkley | Democratic | 2020 |
| Oregon | Ron Wyden | Democratic | 2022 |
| Pennsylvania | Patrick Toomey | Republican | 2022 |
| Pennsylvania | Robert Casey | Democratic | 2018 |
| Rhode Island | Jack Reed | Democratic | 2020 |
| Rhode Island | Sheldon Whitehouse | Democratic | 2018 |
| South Carolina | Lindsey Graham | Republican | 2020 |
| South Carolina | Tim Scott | Republican | 2022 |
| South Dakota | John Thune | Republican | 2022 |
| South Dakota | Mike Rounds | Republican | 2020 |
| Tennessee | Bob Corker | Republican | 2018 |
| Tennessee | Lamar Alexander | Republican | 2020 |
| Texas | John Cornyn | Republican | 2020 |
| Texas | Ted Cruz | Republican | 2018 |
| Utah | Mike Lee | Republican | 2022 |
| Utah | Orrin Hatch | Republican | 2018 |
| Vermont | Bernard Sanders | Independent | 2018 |
| Vermont | Patrick Leahy | Democratic | 2022 |
| Virginia | Mark Warner | Democratic | 2020 |
| Virginia | Tim Kaine | Democratic | 2018 |
| Washington | Maria Cantwell | Democratic | 2018 |
| Washington | Patty Murray | Democratic | 2022 |
| West Virginia | Joe | Democratic | 2018 |
| West Virginia | Shelley Moore Capito | Republican | 2020 |
| Wisconsin | Ron Johnson | Republican | 2022 |
| Wisconsin | Tammy Baldwin | Democratic | 2018 |
| Wyoming | John Barrasso | Republican | 2018 |
| Wyoming | Michael Enzi | Republican | 2020 |
Current Senate