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    Dr. Onuma's Overview

    Dr. Onuma graduated from the SUNY Upstate Medical University in 1990. He works in San Mateo, CA and specializes in Gastroenterology and Hepatology. Dr. Onuma is affiliated with Mills Peninsula Health Services.

    Dr. Onuma's Experience

    Years in Practice: 27

    Dr. Onuma's Specialties

    Gastroenterology, Hepatology

    Dr. Onuma's Education & Training

    Medical School: SUNY Upstate Medical University; Graduated 1990

    Dr. Onuma's Rating

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    Overall Rating


    • Explains conditions & treatments
    • Takes time to answer my questions
    • Provides follow-up as needed
    • View All Ratings

    Dr. Onuma's Accepted Insurance

    Please verify insurance information directly with your doctor's office as it may change frequently.

    • Aetna Basic HMO
    • Aetna Choice POS II
    • Aetna HMO
    • Aetna HMO Deductible Plan CA only
    • Aetna Managed Choice POS Open Access
    • Aetna Savings Plus of CA
    • Aetna Signature Administrators PPO
    • Aetna Vitalidad Plus CA con Aetna
    • BC CA California Care Small Group HMO
    • BCBS Blue Card PPO
    • View More

    Dr. Onuma's Office Information & Appointments

    Office Locations

    Peninsula Gastroenterology-Intestinal Specialists Inc

    100 S Ellsworth Ave Ste 507
    San Mateo, CA 94401
    (650) 342-7432


    Office Hours and Information

    Fax: (650) 342-3239

    Practice Website: Not Available

    Accepting New Patients: Yes

    Medicare Accepted: Yes

    Medicaid Accepted: No

    Monday 9:00 AM - 5:00 PM
    Tuesday 9:00 AM - 5:00 PM
    Wednesday 9:00 AM - 5:00 PM
    Thursday 9:00 AM - 5:00 PM
    Friday 9:00 AM - 5:00 PM
    Saturday Closed
    Sunday Closed

    Other Physicians in Dr. Onuma's Practice

    Dr. Onuma's Hospital Affiliations

    Office Locations