Season 4 of Chicago Med premiered on September 26, 2018. The season had 22 episodes.
- Brian Tee as Dr. Ethan Choi
- Colin Donnell as Dr. Connor Rhodes
- Marlyne Barrett as Maggie Lockwood
- Nick Gehlfuss as Dr. Will Halstead
- Norma Kuhling as Dr. Ava Bekker
- Oliver Platt as Dr. Daniel Charles
- Rachel DiPillo as Dr. Sarah Reese (Episode One Only)
- S. Epatha Merkerson as Sharon Goodwin
- Torrey DeVitto as Dr. Natalie Manning
- Yaya DaCosta as Nurse April Sexton
Notes and Trivia
- The show was renewed for a fourth season by the NBC on May 10, 2018.
- Chicago Med was given a new timeslot: Wednesday at 8 P.M.
- On July 23, 2018 it was announced that Molly Bernard and Colby Lewis are set to recur during Season 4.
- The first promotional video was released on July 25, 2018, regarding the new "Chicago Wednesday'" timeslot.
- Every episode, so far, in Season 4 has a four word title.
- Rachel DiPillo left her role as Dr. Sarah Reese after the first episode of the season.
- The season 4 finale will feature Colin Donnell and Norma Kuhling's final episodes.