NBC announced Ramos and Barnet, both 33, are set to join the hit medical drama as series regulars for its upcoming tenth season.

Ramos will star as Dr. Caitlin Lenox while Barnet will take on the role of Dr. John Frost when the show returns on Wednesday, Sept. 25.

Lenox is "an ED Attending poised to get Gaffney Medical into shape," while Frost is "a pediatric resident who is harboring a secret," a source tells Deadline.

The additions come amid a casting shake-up on the long-time NBC drama series.

PEOPLE learned in June that Dominic Rains -- who played Dr. Crockett Marcel -- was leaving Chicago Med after five seasons.

Jessy Schram, Steven Weber and Luke Mitchell are expected to return, joining original castmembers Oliver Platt, S. Epatha Merkerson and Marlyne Barrett.

In addition to the cast change-up, co-showrunners Diane Frolov and Andy Schneider are leaving the series after nine years with Allen MacDonald set to take over.