Meet-The-Team

Chief Physician Executive, UC Davis Medical Group and Chief Medical Officer for Ambulatory Care, UC Davis Health

Debbie Aizenberg, M.D., M.B.A., is the Chief Physician Executive of UC Davis Medical Group and the Ambulatory Chief Medical Officer at UC Davis Health.

As Chief Physician Executive of UC Davis Medical Group, Aizenberg provides oversight of physician practice operations and assists in developing the UC Davis Medical Group’s overall vision and strategic direction. She works closely with the UC Davis Medical Group Board and UC Davis Health leadership to enhance clinical operations and ensure the most effective care delivery network through a collaborative approach to planning, marketing, and delivering coordinated and patient-centric clinical services.

As Chief Medical Officer, Aizenberg oversees the Ambulatory Care division, providing leadership and direction to the ambulatory enterprise. Her role includes overseeing all ambulatory care practices, including more than 75 clinics at 32 locations in Sacramento and throughout Northern California. Aizenberg leads enhancements in the quality, safety, efficiency, and accessibility of UC Davis Health’s ambulatory practices. She is committed to developing patient-centered care systems and enhancing clinical efficiencies, focusing on health system growth, significant strategic partnerships, and innovative solutions to meet community needs.

Aizenberg, a clinical professor in the Department of Otolaryngology, Head and Neck Surgery, completed the McGill University Med-P program, accelerating her completion of medical school at McGill University in Montreal, Canada. She then completed her general surgery internship and otolaryngology head and neck surgery residency training at UC Davis Health. Aizenberg has a subspecialty certification in complex pediatric otolaryngology. She is a graduate of the Drexel University Hedwig van Ameringen Executive Leadership in Healthcare Program and earned an M.B.A. from UC Berkeley Haas School of Business with academic honors. She has received institutional awards for excellence in service and compassion and has been recognized as a top doctor in regional and national media.

Executive Director of Operations, UC Davis Medical Group

Erin Hubbard serves as executive director of operations for the UC Davis Medical Group. She has more than 28 years of experience at UC Davis, with a background in academic medicine, physician practice management, healthcare administration and operational leadership. During her tenure, she has held progressive leadership roles supporting clinical departments, faculty, physicians and healthcare operations across UC Davis Health.

Erin provides executive leadership and operational oversight for the UC Davis Medical Group. She partners with clinical and administrative stakeholders to support organizational growth, strengthen operational alignment, improve patient access and advance high-quality, patient-centered care. Her work focuses on developing sustainable operational strategies that support both the patient and provider experience and align with UC Davis Health's long-term goals.

Erin holds a Master of Business Administration with a concentration in project management. Her experience includes leading complex operational initiatives, organizational change and strategic healthcare programs.

Director of Physician Contracting and Affiliations, UC Davis Medical Group

Melissa Jost serves as director of physician contracting and affiliations for the UC Davis Medical Group. She leads the strategic and operational functions of the affiliate network and clinical associate model.

Her work includes overseeing physician service agreements and external affiliate partnerships that expand access to primary and specialty care across Northern and Central California. She focuses on regional specialty growth, community partnerships and initiatives that support access, care delivery and population health.

Melissa holds a Master of Science in Health Informatics from the University of California, Davis. She is a certified Project Management Professional and Lean Six Sigma Green Belt. She has been recognized as a Sacramento Business Journal 40 Under 40 honoree and received the Jose King Hero Award.

Administrative Staff

Matthew Startup
Project Manager

Jacqueline Ames
Decision Support Specialist

Sophie Javines
Decision Support Specialist

Harry Randhawa
Decision Support Specialist

Becky Lee
Project Policy Analyst III

Rozana Abuhamdi
Admin Officer II

Suzanne Ziemer
Admin Officer II