Retiring House Republicans:
Will Hurd, Tex. 23rd (Partisan Voter Index, via Cook Political Report: R+1)
Tom Marino, Penn. 12th (R+17)
Jim Sensenbrenner, Wisc. 5th (R+13)
Susan Brooks, Ind. 5th (R+9)
Martha Roby, Ala. 2nd (R+16)
Sean Duffy, Wis. 7th (R+8)
John Shimkus, Ill. 15th (R+21)
Bill Flores, Tex. 17th (R+12)
Rob Woodall, Ga. 7th (R+9)
Paul Mitchell, Mich. 10th (R+13)
Pete Olson, Tex. 22nd (R+10)
Kenny Marchant, Tex. 24th (R+9)
Mike Conaway, Tex. 11th (R+32)
Rob Bishop, Utah 1st (R+26)
Mac Thornberry, Tex. 13th (R+33)
Chris Collins, N.Y. 27th (R+11)
Francis Rooney, Fla. 19th (R+13)
Greg Walden, Ore. 2nd (R+11)
Pete King, N.Y. 2nd (R+3)
Tom Graves, Ga. 14th (R+27)
George Holding, N.C. 2nd (R+7; before redrawn boundaries)
Ted Yoho, Fla. 3rd (R+9)
Mark Walker, N.C. 6th (R+9; before redrawn boundaries)
Mark Meadows, N.C. 11th (R+14; before redrawn boundaries)
Phil Roe, Tenn. 1st (R+28)
Duncan Hunter, Calif. 50th (R+11)
Retiring House Democrats:
José Serrano, N.Y. 15th (D+44)
Dave Loebsack, Iowa 2nd (D+1)
Susan Davis, Calif. 53rd (D+14)
Pete Visclosky, Ind. 1st (D+8)
Denny Heck, Wash. 10th (D+5)
House Republicans quitting to run for higher office:
Bradley Byrne, Ala. 1st (R+15) (Running for Senate)
Greg Gianforte, Mont. at-large (R+11) (Running for Montana governor)
Paul Cook, Calif. 8th (R+9) (Running for San Bernardino County Board of Supervisors)
Roger Marshall, Kan. 1st (R+24) (Running for Senate)
House Democrats quitting to run for higher office:
Ben Ray Luján, N.M. 3rd (D+8) (Running for Senate)
Retiring Senate Republicans:
Lamar Alexander, Tenn. (2020 Senate Race Rating, via Cook Political Report: Likely R)
Mike Enzi, Wyo. (Solid R)
Johnny Isakson, Ga. (Likely R)
Pat Roberts, Kan. (Likely R)
Retiring Senate Democrats:
Tom Udall, N.M. (Likely D)
https://www.axios.com/congress-republicans-democrats-retire-2020-8149a7a1-1878-47fc-b44d-b3970c858f47.html