The characters for a potential medical spinoff from Chicago Fire will be introduced in Episode 19 of the firefighter drama, which will air this spring. Like with Chicago PD, which also started as a planted spinoff from Chicago Fire, the episode will be conceived/written by Chicago Fire creators/executive producers Derek Haas and Michael Brandt, executive producer Matt Olmstead and executive producer Dick Wolf, whose company Wolf Films produces the Chicago Fire/Chicago PD franchise for Universal TV. “There will be an event that brings Chicago Med within Chicago Fire,” NBC chairman Bob Greenblatt said at TCA last month.

Like Chicago Fire and Chicago PD, Chicago Med is envisioned as an ensemble. The list of characters is still murky but it is rumored to possibly include a psychiatrist, a pediatrician and an admissions nurse. Actors will be cast as guest stars with options to become series regulars.

And as has been the case with Chicago PD and any planted pilot, NBC will make a decision on whether to proceed with Chicago Med in May. “Chicago Med is something that we’re just seeding into the system, seeing if there’s a show there that could eventually spin off into itself,” Greenblatt said at TCA.

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The network will be considering Chicago Med alongside medical drama pilot Heart Matters and freshman medical series The Night Shift, which returns for a second season this spring.

In addition to a cast for Chicago Med, I hear NBC is looking to add fresh blood to the mothership series with the introduction of several new characters in future episodes this season that could potentially become regulars. That includes two new firemen and a nurse who would be a love interest for Kelly (Taylor Kinney).