Season 4 of Chicago Med premiered on September 26, 2018. The season consisted of 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
|4x01||Be My Better Half||September 26, 2018||Goodwin clashes with new hospital COO Gwen Garrett while April questions whether Ethan's sister is using drugs again; Charles confronts his past actions.|
|4x02||When to Let Go||October 3, 2018||An overflow of patients is rushed into Chicago Med following an apartment blaze and Rhodes tries to save a firefighter's life, while the two Halstead brothers face their own personal battle.|
|4x03||Heavy Is the Head||October 10, 2018||A sick boy is brought to the hospital, forcing Ethan to face a tough decision that grows into a complicated and dangerous situation.|
|4x04||Backed Against the Wall||October 17, 2018||The CPD pays Dr. Halstead an unexpected visit; Ethan is skeptical of a woman experiencing chronic pain; Natalie takes care of a cancer patient whose brother refuses to help.|
|4x05||What You Don't Know||October 24, 2018||Will must lie to Natalie; Ethan and April uncover compromising information about Emily's boyfriend; Ava isn't sure what to do with a patient who doesn't want treatment.|
|4x06||Lesser of Two Evils||October 31, 2018||Manning and Halstead work quickly to save a physically abused wife; Choi and April discover a shocking truth about a 14-year-old cirrhosis patient; Rhodes and Lanik face off in the ER.|
|4x07||The Poison Inside Us||November 7, 2018||The ED goes on lock-down due to a deadly chemical spill that threatens the lives of patients and leaves one of Med's own in the balance; Rhodes and Manning attempt to perform live-saving surgeries.|
|4x08||Play by My Rules||November 14, 2018||Dr. Charles and Dr. Choi are at odds over surgery. Dr. Rhodes finds himself in hot water.|
|4x09||Death Do Us Part||December 05, 2018||Will and Natalie prepare for their big day, but an unsuspecting Will soon finds himself sidetracked.|
|4x10||All the Lonely People||January 09, 2019||A shooting outside the hospital injures April and leaves the ED shaken up; Halstead returns after a stint in the witness relocation program; Charles and Elsa have an emotional confrontation; Bekker is reluctant to attend an event honoring Rhodes.|
|4x11||Who Can You Trust||January 16, 2019||Halstead takes heat for making an unauthorized move to treat his pregnant patient. Choi becomes personally invested when treating a homeless veteran. Rhodes and Bekker deal with a patient who desperately needs a liver transplant.|
|4x12||The Things We Do||January 23, 2019||Dr. Halstead rushes to rescue Dr. Manning from a chopper crash. Drama between Dr. Rhodes and Dr. Bekker boils over. Dr. Charles and Dr. Choi work to help a patient with their addiction. April helps Elsa deal with losing her first patient.|
|4x13||Ghosts in the Attic||February 06, 2019||Halstead hides the theft of his gun from a suspicious Manning. Tensions are still high between Connor and Bekker, who take a risk operating on an HIV-positive patient. Hank breaks down when he sees a patient from his past.|
|4x14||Can't Unring That Bell||February 13, 2019||Connor, who is in hot water with the hospital's Oversight Committee, handles a gunshot victim with unexpected ties to Halstead. Maggie feels guilty about the return of a former patient. Charles has an awkward first date.|
|4x15||We Hold These Truths||February 20, 2019||Natalie and Maggie witness a pickup truck plow through a street fair and must make tough decisions on the fly. At the hospital, doctors and nurses are on high alert with the influx of patients. Dr. Charles' ex-wife comes to town with news.|
|5x16||Old Flames, New Sparks||February 27, 2019||Halstead treats a woman on the verge of freezing to death. Dr. Charles' ex-wife receives some concerning news. Choi handles a lymphoma patient with viral meningitis and a complicated family. Manning makes a house call.|
|4x17||The Space Between Us||March 27, 2019||When a car unexpectedly smashes through the ambulance bay doors, Dr. Choi makes some difficult decisions in an effort to save a worker trapped beneath the wreckage and April, who's also in danger.|
|4x18||Tell Me the Truth||April 03, 2019||Dr. Rhodes receives an alarming phone call that prompts him to rush out in the middle of an important surgery. Dr. Halstead comes to the aid of an FBI agent who is brought into the ER, but he suspects there is more to the story than he is being told. Dr. Manning and Dr. Choi find themselves on opposite sides of a major disagreement over doctor-patient confidentiality.|
|4x19||Never Let You Go||April 24, 2019||The hospital goes into lockdown mode when a man with a gun holds medical staff hostage. Goodwin is forced to make a tough decision. Dr. Rhodes begins to realize his time with his father is getting short.|
|4x20||More Harm Than Good||May 08, 2019||Dr. Charles and Dr. Manning disagree on how to handle a patient who they discover is poisoning herself. Dr. Rhodes throws some serious accusations at Dr. Bekker. Dr. Halstead has suspicions about Natalie's new boyfriend. Dr. Choi tends to Bernie.|
|4x21||Forever Hold Your Peace||May 15, 2019||Caroline shares news that forces Dr. Charles to make a serious decision about their relationship. Maggie meets her sister's new boyfriend but danger may lie ahead. Dr. Rhodes experiences a huge loss. Dr. Choi and April face an unexpected challenge.|
|4x22||With a Brave Heart||May 22, 2019||Dr. Charles and Caroline set some major plans; Ava fights to keep her relationship with Connor. Agent Lee informs Will of news that may put his life in danger.|
Notes and Trivia
- The show was renewed for a fourth season by 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 were set to recur during Season 4.
- The first promotional video was released on July 25, 2018, regarding the new "Chicago Wednesday'" timeslot.
- Every episode in this season 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 featured Colin Donnell and Norma Kuhling's final episodes.