--- title: "Dr. Wei-Fang J. Ko | Gastroenterologist in Hayward, CA | Sutter Health" description: "Dr. Wei-Fang J. Ko, M.D. practices Gastroenterology in Hayward, CA and Castro Valley, CA. Accepting new patients." url: "https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782" --- 1. [Home](https://www.sutterhealth.org/) / 2. [Find a provider](https://www.sutterhealth.org/find-provider) / 3. Wei-Fang J. Ko, M.D. ![Wei-Fang J. Ko, M.D.](https://dyn.mktgcdn.com/p/R7Jimn2Wf254Efq0fElAKStYbD7BatkbkMTz_1lYCYU/1.0000/fit=crop,gravity=auto,dpr=2,width=230,height=230) # Wei-Fang J. Ko, M.D. ## Gastroenterology - Accepting new patients [27206 Calaroga AvenueSuite 212Hayward, CA 94545](https://www.google.com/maps/dir/?api=1&destination=27206+Calaroga+Avenue+Hayward%2C+CA+94545+US) [+1 more location](https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#provider-locations) ## Schedule appointment [510-887-1777](tel:+15108871777) Jump to: - [About](https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#provider-about) - [Locations](https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#provider-locations) - [Services](https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#provider-services) ## About Dr. Ko Languages English Gender Male ## Education and training **Medical school:** Taipei Medical College **Residency:** University of Minnesota, Internal Medicine **Fellowship:** University of California, San Francisco, Gastroenterology ## Board certifications - Gastroenterology - Board Certified ## Affiliations ### Hospitals - Sutter Eden Medical Center ## Care locations 27206 Calaroga Avenue Suite 212 Hayward, CA 94545 [Get directions](https://www.google.com/maps/dir/?api=1&destination=27206+Calaroga+Avenue+Hayward%2C+CA+94545+US) [510-887-1777](tel:+15108871777) 510-887-0324 19845 Lake Chabot Rd. Suite 104 Castro Valley, CA 94546 [Get directions](https://www.google.com/maps/dir/?api=1&destination=19845+Lake+Chabot+Rd.+Castro+Valley%2C+CA+94546+US) [510-537-4415](tel:+15105374415) 510-537-8265 ## Related services offered by Sutter - [Gastroenterology](https://www.sutterhealth.org/services/gastroenterology) - [Gastroenterology evaluation and diagnostic](https://www.sutterhealth.org/services/gastroenterology-evaluation-diagnostic) ### Disclaimer _This provider directory is provided as a convenience to you. It is not intended as a recommendation, referral or endorsement of any particular provider. Physicians are not employees or agents of Sutter Health or its subsidiaries. The information is submitted by each doctor and we make no guarantee or warranty as to the accuracy of the information. You should verify the accuracy of the information directly with the provider's office._ _All doctors on this site are in the Sutter system. Doctors meeting your search criteria are presented in order of relevance based on search criteria, based on those providers with appointment availability._ [_Find out more about star ratings_](https://www.sutterhealth.org/star-ratings)_._ ```json {"@context":"https://schema.org","@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org","logo":"https://www.sutterhealth.org/static/images/sutter-health-logo.svg","address":{"@type":"PostalAddress","streetAddress":"2200 River Plaza Drive","addressLocality":"Sacramento","addressRegion":"CA","postalCode":"95833","addressCountry":"US"},"areaServed":{"@type":"AdministrativeArea","name":"California"},"sameAs":["https://www.facebook.com/SutterHealth","https://www.instagram.com/sutterhealth/","https://x.com/SutterHealth","https://www.youtube.com/sutterhealth","https://www.linkedin.com/company/sutter-health","https://en.wikipedia.org/wiki/Sutter_Health"]} ``` ```json {"@context":"https://schema.org","@type":"BreadcrumbList","@id":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#breadcrumblist","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://www.sutterhealth.org/"},{"@type":"ListItem","position":2,"name":"Find a provider","item":"https://www.sutterhealth.org/find-provider"},{"@type":"ListItem","position":3,"name":"Wei-Fang J. Ko, M.D."}]} ``` ```json {"@context":"https://schema.org","@type":"IndividualPhysician","@id":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782","areaServed":[{"@type":"GeoCircle","geoMidpoint":{"@type":"GeoCoordinates","latitude":37.632322,"longitude":-122.086906},"geoRadius":"80467"},{"@type":"GeoCircle","geoMidpoint":{"@type":"GeoCoordinates","latitude":37.6999171,"longitude":-122.0882349},"geoRadius":"80467"}],"description":"Dr. Wei-Fang J. Ko, M.D. practices Gastroenterology in Hayward, CA and Castro Valley, CA. Accepting new patients.","faxNumber":"5108870324","hasCertification":[{"@type":"Certification","name":"Board Certification - Gastroenterology"}],"hasCredential":[{"@type":"EducationalOccupationalCredential","credentialCategory":"Medical school","name":"Taipei Medical College"},{"@type":"EducationalOccupationalCredential","credentialCategory":"Residency","name":"University of Minnesota, Internal Medicine"},{"@type":"EducationalOccupationalCredential","credentialCategory":"Fellowship","name":"University of California, San Francisco, Gastroenterology"}],"hospitalAffiliation":[{"@type":"Hospital","name":"Sutter Eden Medical Center"}],"identifier":{"@type":"PropertyValue","propertyID":"US NPI","value":"1417068081"},"image":{"@type":"ImageObject","representativeOfPage":true,"description":"Wei-Fang J. Ko","contentUrl":"https://dyn.mktgcdn.com/p/R7Jimn2Wf254Efq0fElAKStYbD7BatkbkMTz_1lYCYU/1.0000/fit=crop,gravity=auto,width=480,height=480"},"isAcceptingNewPatients":true,"knowsLanguage":[{"@type":"Language","name":"English"}],"parentOrganization":{"@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org"},"practicesAt":[{"@type":"MedicalClinic","address":{"@type":"PostalAddress","streetAddress":"27206 Calaroga Avenue","addressLocality":"Hayward","addressRegion":"CA","postalCode":"94545","addressCountry":"US"},"geo":{"@type":"GeoCoordinates","latitude":37.632322,"longitude":-122.086906},"telephone":"5108871777","faxNumber":"5108870324","hasMap":{"@type":"Map","url":"https://www.google.com/maps/search/?api=1&query=27206+Calaroga+Avenue+Hayward%2C+CA+94545+US&sll=37.632322%2C-122.086906"}},{"@type":"MedicalClinic","name":"Gastroenterology Specialists Medical Group","address":{"@type":"PostalAddress","streetAddress":"19845 Lake Chabot Rd.","addressLocality":"Castro Valley","addressRegion":"CA","postalCode":"94546","addressCountry":"US"},"geo":{"@type":"GeoCoordinates","latitude":37.6999171,"longitude":-122.0882349},"telephone":"5105374415","faxNumber":"5105378265","hasMap":{"@type":"Map","url":"https://www.google.com/maps/search/?api=1&query=19845+Lake+Chabot+Rd.+Castro+Valley%2C+CA+94546+US&sll=37.6999171%2C-122.0882349"}}],"medicalSpecialty":[{"@type":"MedicalSpecialty","name":"Gastroenterology","sameAs":["https://schema.org/Gastroenterologic"]}],"memberOf":[{"@type":"Organization","name":"Sutter Eden Medical Center"}],"name":"Wei-Fang J. Ko, M.D.","telephone":"5108871777","mainEntityOfPage":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782","url":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782","usNPI":"1417068081","sameAs":["https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#Person","https://npiregistry.cms.hhs.gov/provider-view/1417068081"]} ``` ```json {"@context":"https://schema.org","@type":"Person","@id":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782#Person","name":"Wei-Fang J. Ko, M.D.","additionalName":"J.","alumniOf":[{"@type":"EducationalOrganization","name":"Taipei Medical College"}],"familyName":"Ko","gender":"Male","givenName":"Wei-Fang","hasOccupation":{"@type":"Occupation","name":"Gastroenterologist"},"honorificPrefix":"Dr.","honorificSuffix":"M.D.","jobTitle":"Physician","sameAs":"https://www.sutterhealth.org/find-provider/dr-wei-fang-j-ko-1046244782","knowsLanguage":[{"@type":"Language","name":"English"}],"worksFor":{"@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org"}} ```