Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Dr. Geraldine Gan Tan, MD

Individual provider Internal Medicine Physician · NPI 1699744086

Dr. Geraldine Gan Tan, MD is an Internal Medicine Physician in Walnut Creek, California. Licensed in California. Registered with an NPI since 2006.

Licensed in
CA
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1220 Rossmoor Pkwy
Walnut Creek, CA 94595-2501
Phone: (925) 947-3393
Fax: (925) 947-3396
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Hospitalist Physician (primary) Taxonomy 208M00000X · Licence A81859 (CA)
Internal Medicine Physician Taxonomy 207R00000X · Licence A81859 (CA)

Record details

NPI number1699744086
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedMarch 16, 2006
Last updated in NPPESSeptember 29, 2015

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