Clinical Associates


Sean Adelman, MD
Orthopedic Surgeon

Scott Armstrong
President & CEO

Susan Carol Bradford
Manager, Screening and Outreach Programs

Christopher Cable, MD
Medical Director, Medical Specialties

Ryan Caldeiro, MD
Program Chief, Chemical Dependency Services

Wellesley Chapman, MD
Medical Director, Innovation and Development

Eric Chen, MD, PhD
Program Chief, Hematology/Oncology

Jane Dimer, MD
Physician, Obstetrics & Gynecology; Chair, Credentialing & Privileging Committee, Western Washington

Paul Fletcher, MD
Medical Director, North Service Area, Group Practice Division

Matt Handley, MD
Medical Director, Clinical Improvement & Prevention

Fred Heidrich, MD, MPH
Family Physician

Charlie Jung, MD
Orthopedic Surgeon

Bob Karl, MD
Medical Director, Radiology & Mammography

Sarah Levy, MD
Medical Director, Continuum of Care

Larry Marx, MD
Medical Director, Behavioral Health Support Services

Dave McCulloch, MD, MPH
Medical Director, Clinical Improvement

Susie McDonald, BSN, MN
Director, Clinical Improvement & Prevention

Diana Birkett Rakow, MPH, MBA
Executive Vice President of Marketing & Public Affairs; President, Group Health Foundation

Kim Riddell, MD
Physician, Clinical Pathology
Medical Director, Clinical Laboratories

Paul Sherman, MD
Executive Medical Director, Health Plan Services

Stephen L. Tarnoff, MD
President & Chief Medical Executive, Group Practice Division

Chris Thayer, MD
Medical Director, Clinical Knowledge and Support 

Barbara Trehearne, PhD, RN
Vice President of Clinical Excellence & Integration, Chief Nurse

Kimberly Wicklund, MPH
Manager, Patient Engagement

Lisa Williams, MD, MPH
Dermatologist

Lee-Ching Zhu, MD
Staff Pathologist