Rady Children’s Health announced the departure of one of its top executives on Thursday.

Dr. Patrick Frias served as the president and CEO of San Diego-based Rady Children’s Hospital and Health Center from 2018 until its merger with Children’s Hospital of Orange County early last year. Since then, he’s been the co-president and CEO of the combined entity, alongside CHOC’s longtime former head, Kimberly Chavalas Cripe.

Frias accepted a position as the leader of Children’s Healthcare of Atlanta and is expected to transition to his new role this summer, according to Rady Children’s. Following Frias’ departure, the organization said Cripe will become Rady Children’s sole president and CEO.

 NBC 7’s Jackie Crea spoke with Rady CEO Patrick Frias about the two hospitals joining forces.

“I am deeply grateful to the extraordinary teams across Rady Children’s Health and to our community partners for supporting our mission,” Frias said in a statement on Rady Children’s website. “I look forward to bringing the lessons learned here to my new role and continuing to partner with Kim and other healthcare leaders across the country in advocating for what’s best for children and families.”

Frias did not provide more details about his reason for leaving in the statement.

Rady Children’s Health operates three hospitals: Rady Children’s Hospital in San Diego and CHOC’s two locations in Orange and Mission Viejo. Altogether, the organization has more than 13,000 employees and 2,000 medical staff, making it “one of the largest pediatric healthcare systems in the nation,” according to a news release.