DR. KARTHIKEYAN VISWANATHAN DO
NPI 1396128336
Internal Medicine in Los Altos, CA

Q: What is Karthikeyan Viswanathan's NPI number?

The NPI number for Karthikeyan Viswanathan is 1396128336. It was assigned to this individual provider in the NPPES registry on July 8, 2015.

Q: What is Karthikeyan Viswanathan's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Active since July 08, 2015PECOS Enrolled

4546 EL CAMINO REAL STE B7, LOS ALTOS, CA 94022(866) 362-4246(650) 260-6030 Get Directions Write a Review

NPPES record last updated: August 21, 2025. Verified against the NPPES registry weekly; last sync: July 26, 2026.

Record update history: Dec 16, 2022, Apr 26, 2022, Nov 11, 2019 and 1 more (4 updates tracked since 2016).

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About Dr. Karthikeyan Viswanathan Do NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. KARTHIKEYAN VISWANATHAN DO (NPI 1396128336) is an individual internal medicine provider in Los Altos, California, licensed in California (20A19044) and active in the NPI registry since July 2015. He is enrolled in Medicare PECOS and is a graduate of Other (2014).

NPPES Registry Identity

NPI1396128336

Entity TypeIndividualMale

Primary Taxonomy207R00000X

Provider Legal NameDR. KARTHIKEYAN VISWANATHANCredential: DO

Location Address4546 EL CAMINO REAL STE B7Los Altos, CA 94022-1069

Mailing Address4546 El Camino Real Ste B7Los Altos, CA 94022-1069 · (866) 362-4246 · Fax (650) 260-6030

Phone(866) 362-4246

Fax(650) 260-6030

Sole ProprietorNo

Medical School CMSOtherGraduated 2014

Enumeration DateJuly 8, 2015

Last NPPES UpdateAugust 21, 20254 updates tracked since enumeration

NPPES CertifiedAugust 21, 2025

✔ NPI 1396128336 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207R00000X

License✔ Licensed in CA · 20A19044

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

4546 EL CAMINO REAL STE B7, Los Altos, CA 94022

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Karthikeyan Viswanathan Do is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID6103251442

PECOS Enrollment IDI20250116000720

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 2

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Hemoglobin a1c level 83036

Hemoglobin A1c (HbA1c) is a test that measures your average blood sugar level over the past 2-3 months. It's used to monitor how well diabetes is being controlled. High levels may indicate that your diabetes treatment plan needs adjustment.

14 services12 patients

Automated urinalysis test 81003

An automated urinalysis test is a routine examination that checks your urine for various substances. It can help identify potential health issues such as kidney problems or diabetes. The test uses a machine to analyze a small urine sample, providing quick and accurate results.

13 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94022 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$156.67 typical visit price

range $70.37 – $206.04

Typical copayment $39.16 (range $17.59 – $51.51)

Most-billed visit code 99204

Established Patient

$121.77 typical visit price

range $23.96 – $169.60

Typical copayment $30.44 (range $5.99 – $42.40)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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Other Providers at the Same Location NPPES 13

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. LAURENCE H. TECOTT M.D.

Psychiatry & Neurology (Psychiatry)