
Medical Directors
The PHC medical directors are proud of their role in promoting access to high-quality health care for the Medi-Cal population in PHC's 24 counties. The medical directors are responsive to inquiries from our clinician network, pro-active in addressing quality and systems issues they encounter, and logical and rational in their approach to complex medical scenarios.
Chief Medical Officer:
Robert Moore, MD MPH MBA, Family Medicine
Regional Medical Directors:
Northern Region (Del Norte, Humboldt, Lassen, Modoc, Shasta, Siskiyou, and Trinity): Jeff Ribordy, MD MPH, Pediatrics
Southeast Region (Napa, Solano, and Yolo): Colleen Townsend, MD, Family Medicine
Southwest Region (Lake, Marin, Mendocino, Sonoma): Marshall Kubota, MD, Family Medicine
Eastern Region (Butte, Colusa, Glenn, Nevada, Placer, Plumas, Sierra, Sutter, Tehama, and Yuba): R. Douglas Matthews, MD, Gastroenterology
Associate Medical Director for Quality:
Mark Netherda, MD, Family Medicine
Associate Medical Directors:
Aaron Thornton, MD, MBA, Internal Medicine
Bettina Spiller, MD, Family Medicine
Bradley Cox, DO, Family Medicine
David Katz, MD, Family Medicine
James Cotter, MD MPH, Family Medicine
Mark Glickstein, MD, Internal Medicine
Teresa Frankovich, MD MPH, Pediatrics