Deadline reports that all of the departures are for creative reasons.
Donnell tweeted about his exit, saying that the news was accurate.
"Sorry to say that this is true. I love my #ChicagoMed #OneChicago family dearly. And a special thank you to all the fans that have made these last four seasons so amazing," he said.
"It's been an honor to be a part of such a great trio of shows and in the @WolfEnt family. I know that there's great things coming for Season 5 and I can't wait to see what they are along with all you fans," he said in another tweet.
Chicago P.D., Chicago Fire, and Chicago Med have all been renewed for the 2019/2020 season. NBC had no comment on the exits.
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