Allegheny Health Network tapped West Penn Hospital’s top official Monday to lead a regional affiliation of doctors and their practices.

Dr. Brian Johnson, who’s been president of West Penn Hospital since 2020, was named medical director and chief population health officer at Physician Partners of Western PA.

He succeeds Dr. William Johnjulio, who is returning to the network’s primary care institute to focus on treating patients.

Allegheny Health Network launched the group in 2017 to promote collaboration between doctors, insurers and hospital systems. It’s built on the principles of value-based medicine — the idea doctors should be paid based on the cost and quality of care, rather than a fixed fee for each service.

“The more clinicians work together, the better we can serve our communities and our patients,” Johnson said in a statement.

Physician Partners has roughly 3,500 members — a mix of Allegheny Health Network and independent doctors.

With Johnson is his new role, Allegheny Health Network Chief Operating Officer Lou Baverso will pull double duty as West Penn’s interim president.

Allegheny Health Network announced three other leadership changes Monday:

• Dr. Saad Mahmood will replace Dr. Allan Philp Jr. as chief medical officer at Allegheny General Hospital. Philp will remain on staff at the hospital and transition back to a full-time clinical role.

• Dr. Alan Murdock, who has served as director of Allegheny Health Network’s general surgery residency program since 2017, will become interim network director of trauma.

• Dr. Giath Shari has been appointed chief medical officer at Forbes Hospital. Shari has led the hospital’s medicine department since 2022. He succeeds Dr. Ezz-Eldin Moukamal, who was promoted last year from Forbes’ chief medical officer to chief quality officer for the whole network.