EXCLUSIVE: There are changes in the upper ranks of two Chicago series. Chicago Fire co-creator/executive producer/co-showrunner Michael Brandt is leaving, along with the series’ executive producer/director Joe Chappelle. Over at Chicago P.D., departing is executive producer/director Mark Tinker. That follows the recent exit of Chicago P.D. co-creator/executive producer/showrunner Matt Olmstead as Dick Wolf is shaking things up on the two strongest series in the franchise.

Michael Brandt, along with Derek Haas, wrote the Chicago Fire pilot script, which helped launch a big drama franchise for NBC. The two have been credited as executive producers on all Chicago series and have been hands-on involved in Chicago Fire, serving as co-showrunners this season. Haas will continue as a solo showrunner on the series, which has been renewed for a sixth season. In its current fifth season, Chicago Fire has been NBC’s second-highest-rated and most watched drama series behind breakout This Is Us.

Chappelle has served as executive producer and director on the mothership series since its launch. He directed the Chicago Fire episodes that served as planted pilots for spinoffs Chicago P.D. and Chicago Med. 

I hear former Chicago Fire camera operator Reza Tabrizi, who has been directing episodes of Fire and P.D., in talks to succeed him as executive producer.

Tinker has been executive producer on Chicago P.D. since the cop drama’s 2014 launch. The series has been renewed for a fifth season.

Wolf is known for switching things up and promoting within on his shows. Recently, Rick Eid, who was showrunner on Law & Order: SVU this season, moved over to run Chicago P.D. next season, succeeding Olmstead.