Chicago Med returns for its 12th season on 7 October alongside the rest of the One Chicago franchise, and showrunner Allen McDonald has confirmed the season will open with a three-month time jump. The change matters because it reshapes one of the show's central relationships, moving the slow-burn dynamic between Dr Hannah Asher and Dr Dean Archer into more complicated territory just as viewers expected resolution following major developments at the end of season 11.

Season 11 ended with Hannah giving birth to her and Dean's child and Dean confessing his feelings for her, but the new season finds Hannah still unable to tell him how she feels, partly because of the baby. The pair are now living together to care for their daughter Mabel, and Hannah, struggling with isolation during maternity leave, has a difficult visit to the emergency department in the premiere. McDonald has not revealed whether or when Hannah will return to work, or whether she and Dean will ultimately get together, leaving the storyline's outcome open. All series regulars, the showrunner and several recurring guest stars are returning, and the season's episode count has not been reduced.