News Release

PHOENIX [April 11, 2024] – In a move that strengthens the medical leadership of Phoenix Children’s, the health system today announced a new chief medical officer (CMO) as well as the expansion of the CMO office to include two associate CMOs.

Blake Bulloch, MD, MBA, has been tapped as chief medical officer, with Kelly Kelleher, MD, and Liz Zorn, MD, named associate CMOs.

“Dr. Bulloch is a world-class physician leader who will continue our longstanding legacy of continuous improvement in patient care and outcomes,” said Jared Muenzer, MD, MBA, chief physician executive of Phoenix Children’s and chief operating officer of Phoenix Children’s Medical Group. “After an extensive nationwide search for a new CMO, it was clear we needed a leader who knows our health system inside and out and Blake is exactly the right person to serve in this critical role.”

Dr. Bulloch joined Phoenix Children’s in 2002 and has served as division chief of emergency medicine since 2012. He has also served as president and vice president of the medical staff and currently chairs the Phoenix Children’s Medical Group Governance Council. A national search is now underway for a new division chief of emergency medicine.

“I’m honored to serve as CMO and look forward to working closely with Drs. Kelleher and Zorn on this leadership team,” said Dr. Bulloch. “Together, we will partner with Phoenix Children’s medical staff on safety and quality efforts across our growing health system.” 

Amid rapid physical expansion across Arizona – including the opening of two additional hospitals in 2024 – health system leaders knew it was time to expand the CMO office. Naming two associate CMOs is one of many efforts to ensure patients receive Phoenix Children’s signature high-quality, patient-family centered healthcare at every location.

“When we created these new positions, Drs. Kelleher and Zorn immediately rose to the top,” said Dr. Muenzer. “Over the course of their long careers at Phoenix Children’s, they have demonstrated an unmatched commitment to the families we serve, not to mention exceptional clinical skills. This was especially clear during the pandemic when they helped Phoenix Children’s navigate one of the toughest periods in our 40-year history.”

Indeed, Dr. Kelleher and Dr. Zorn helped lead the COVID-19 Command Center during the pandemic. They worked alongside retiring CMO Michael Ritchey, MD, during a critical time for Phoenix Children’s.

Dr. Kelleher has been at Phoenix Children’s since her medical career began, first serving as chief resident and then joining Phoenix Children’s Medical Group in 2012 as a pediatric hospitalist. In 2017, she was named medical director of patient safety and quality before her promotion in 2020 to Chief Quality and Safety Officer.

Dr. Zorn, a pediatric critical care specialist, joined Phoenix Children’s in 1998. She was named medical director of the pediatric intensive care unit in 2015 and vice section chief in 2018. She is a previous medical staff president and has served as the medical director of the quality department since 2020.

Drs. Bulloch, Kelleher and Zorn will continue treating patients to ensure they stay close to patient-family care and understand how best to support Phoenix Children’s medical staff. 

The CMO position became available when Michael Ritchey, MD, who has served in the role for six years, announced he would retire in 2024. Dr. Ritchey will retire from medicine in December. Until then, he will work closely with the CMO office and Phoenix Children’s senior leadership to ensure a seamless transition.

“Anyone who has had the pleasure of working with Dr. Ritchey knows he is an exceptional physician leader. His work to transition the new CMO leadership team is yet another example of his commitment to providing the best care for children and families,” said Dr. Muenzer. “He’s also a top expert in pediatric urology who has made significant research and clinical contributions to his field. We will miss him dearly and wish him all the best in his retirement.”