After a promising start, the latest installment in Dick Wolf’s Chicago franchise, Chicago Med, has received a five-episode back order from NBC, bringing its freshman season to 18 episodes. (The size of the pickup, four episodes short of the standard 22 episodes, can be explained by the fact the Chicago Med launched on November 17, nearly two months into the season.)

Four telecasts into its run, Chicago Med has averaged a 2.0 rating in adults 18-49 and 8.9 million viewers overall in Live+Same Day, with the show consistently winning its time period.

Like mothership Chicago Fire, Chicago Med has shown growth as its freshman season progresses. The medical drama saw its 18-49 delivery rise in Week 3 by 11% (to a 2.0 from a 1.8) and by another 5% in its fourth week (2.1 vs. 2.0), making it the only new show out of 23 on the Big 4 networks so far this fall to grow two of the first three weeks after its premiere.

With Chicago Fire and Chicago P.D. already renewed for next season and Chicago Med off to a solid start, is the long-rumored legal fourth installment, aka Chicago Law, far off?

Set at a hospital in the Windy City, Chicago Med stars Oliver Platt, S. Epatha Merkerson, Nick Gehlfuss, Yaya DaCosta, Rachel DiPillo, Colin Donnell, Brian Tee and Torrey DeVitto. Wolf, showrunners Andrew Schneider & Diane Frolov, Matt Olmstead, Michael Brandt, Derek Haas, Arthur Forney, Danielle Gelber and Peter Jankowski executive produce for Universal Television and Wolf Films.