Patient Portal; Financial Responsibility; ... (760) 529-9503 Dr. Liu (760) 639-1714 Dr. Zimmermann 3601 Vista Way #201, Oceanside, CA 92056. Office Hours. We are currently available Monday - Friday Moring hours 8:15 AM -12:30 PM Lunch break 12:30-1:30 PM (OFFICE IS CLOSED) ... Dr. Andres Zimmermann MD | Internal Medicine and Geriatric ....