ABC is returning to the firehouse.

The Disney-owned broadcast network has handed out an early fourth-season renewal for Grey's Anatomy spinoff Station 19. The news comes as the current third cycle — the first since Grey's showrunner Krista Vernoff took over the series — is having its most watched season.

"Krista Vernoff is a sharp, superb storyteller and we're so grateful to her — along with the talented cast and crew — for all they've done to make Station 19 thrive this season," said ABC entertainment president Karey Burke. "This addictive, rich show is hitting series highs this year for a reason, and we can't wait to deliver more great stories to our passionate audience."

In its third season, Station 19 ranks as the No. 1 program in its new Thursday at 8 p.m. slot in total viewers and the advertiser-coveted adults 18-49 demo. Its overall audience is up 9 percent year-over-year and, with 35 days of delayed viewing, it averages 13.5 million total viewers and a 3.7 in the demo. Station 19 this season was moved to open Thursdays as a lead-in for Grey's Anatomy, which moved back an hour to its original 9 p.m. slot. Under Vernoff the two shows have been more intertwined, with four more substantial crossovers planned this season.

Grey's Anatomy, ABC's longest-running primetime original, is already renewed for the 2020-21 broadcast season, when it will enter its impressive 17th cycle. In addition to running both Grey's and Station 19, Vernoff also has Rebel, an Erin Brockovich legal drama pilot, in contention for next season. Katey Sagal and Andy Garcia star.

Along with Grey's, Station 19 joins medical drama The Good Doctor as having received early renewals for next season at ABC.

Jaina Lee Ortiz, Jason George, Boris Kodjoe, Grey Damon, Barrett Doss, Jay Hayden, Okieriete Onaodowan, Danielle Savre and Miguel Sandoval star in Station 19.