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

William J Tsai MD Inc

Organization Internal Medicine Physician · NPI 1114277738

William J Tsai MD Inc is an Internal Medicine Physician in Irvine, California. Licensed in California. Registered with an NPI since 2012.

Licensed in
CA
In the registry since
2012
What do these letters mean?
Inc — Incorporated
A form of business registration, not a clinical qualification.

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Practice location Address checks out

19742 Macarthur Blvd Ste 101
Irvine, CA 92612-2432
Phone: (949) 955-0202
Fax: (949) 955-0203
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence A71679 (CA)

Record details

NPI number1114277738
Entity typeOrganization (Type 2)
Organization subpartNo
Authorized official William Tsai — Pres/Ceo · (949) 955-0202
NPI enumeratedSeptember 11, 2012
Last updated in NPPESSeptember 11, 2012
Mailing address19742 Macarthur Blvd, Suite 101, Irvine, CA 92612-2432

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