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

Dr. Karthikeyan Viswanathan, DO

Individual provider Internal Medicine Physician · NPI 1396128336

Dr. Karthikeyan Viswanathan, DO is an Internal Medicine in Los Altos, California. Qualified in 2014, 12 years ago. Licensed in California.

Years since qualifying
12
Licensed in
CA
In the registry since
2015
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

4546 El Camino Real Ste B7
Los Altos, CA 94022-1069
Phone: (866) 362-4246
Fax: (650) 260-6030
Show map & directions

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

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 20A19044 (CA)

Record details

NPI number1396128336
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedJuly 8, 2015
Last updated in NPPESAugust 21, 2025
Certification dateAugust 21, 2025
Mailing address4546 El Camino Real Ste B7, Los Altos, CA 94022-1069

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2014 (12 years in practice)
Accepts Medicare assignment Not indicated
Practice locations5 on file with Medicare

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