Two years:
Class II terms run from the beginning of the 117th Congress on January 3, 2021, to the end of the 119th Congress on January 3, 2027. Senators in Class II were elected to office in the November 2020 general election, unless they took their seat through appointment or special election.
Democrats
Booker, Cory A. (D-NJ)
Coons, Christopher A. (D-DE)
Durbin, Richard J. (D-IL)
Hickenlooper, John W. (D-CO)
Luján, Ben Ray (D-NM)
Markey, Edward J. (D-MA)
Merkley, Jeff (D-OR)
Ossoff, Jon (D-GA)
Peters, Gary C. (D-MI)
Reed, Jack (D-RI)
Shaheen, Jeanne (D-NH)
Smith, Tina (D-MN)
Warner, Mark R. (D-VA)
Republicans
Capito, Shelley Moore (R-WV)
Cassidy, Bill (R-LA)
Collins, Susan M. (R-ME)
Cornyn, John (R-TX)
Cotton, Tom (R-AR)
Daines, Steve (R-MT)
Ernst, Joni (R-IA)
Graham, Lindsey (R-SC)
Hagerty, Bill (R-TN)
Hyde-Smith, Cindy (R-MS)
Lummis, Cynthia M. (R-WY)
Marshall, Roger (R-KS)
McConnell, Mitch (R-KY)
Mullin, Markwayne (R-OK)
Ricketts, Pete (R-NE)
Risch, James E. (R-ID)
Rounds, Mike (R-SD)
Sullivan, Dan (R-AK)
Tillis, Thom (R-NC)
Tuberville, Tommy (R-AL)
The Senate map in 2026 won’t produce much of a change.
The Republicans might flip Georgia and the Democrats Maine.(if Collins retires)