Doctor profile · Federal record
Dr. Karthikeyan Viswanathan, DO
Internal Medicine Physician (CMS: Internal Medicine) · Los Altos, CA
- NPI 1396128336
- Accepts Medicare
- 12 yrs in practice
- Male
- Group practice
- No sanctions
Practice & contact
- Primary practice
-
4546 El Camino Real Ste B7
Los Altos, CA 940221069
(866) 362-4246
fax (650) 260-6030
Credentials & registration
- NPI registered
- July 2015 — 11 yrs on file
- Profile last updated
- August 21, 2025
- Year of graduation
- 2014 — 12 yrs since
- Specialty taxonomy
- 207R00000X — NUCC code
- State license (1)
- California #20A19044
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1396128336. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
188
Distinct HCPCS
10
Medicare allowed
$1,862
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
83036 |
Hemoglobin a1c level | 29 | 25 | $10 | |
85025 |
Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count | 24 | 23 | $8 | |
80053 |
Blood test, comprehensive group of blood chemicals | 21 | 21 | $10 | |
82043 |
Urine microalbumin (protein) level | 19 | 18 | $6 | |
82570 |
Creatinine level to test for kidney function or muscle injury | 19 | 18 | $5 | |
80048 |
Blood test, basic group of blood chemicals (calcium, total) | 18 | 17 | $8 | |
82465 |
Cholesterol level | 17 | 15 | $4 | |
81003 |
Automated urinalysis test | 16 | 16 | $2 | |
87811 |
Detection test by immunoassay with direct visual observation for severe acute respiratory syndrome coronavirus 2 (covid-19) | 13 | 12 | $41 | |
84443 |
Blood test, thyroid stimulating hormone (tsh) | 12 | 12 | $16 |
In context: peer comparison
Among 8 peers in Los Altos Internal Medicine Physician, average services per provider: 59. This provider delivers 3.2× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
67
Patients
28
Total drug cost
$1,458
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Atorvastatin Calcium | Generic | 34 | 17 | $892 |
| Lisinopril | Generic | 20 | 11 | $291 |
| Amlodipine Besylate | Generic | 13 | 0 | $275 |
Frequently asked questions
What is Dr. Karthikeyan Viswanathan's medical specialty?
Dr. Karthikeyan Viswanathan practices Internal Medicine Physician in Los Altos, CA.
Where does Dr. Karthikeyan Viswanathan practice?
Dr. Karthikeyan Viswanathan practices at 4546 El Camino Real Ste B7, Los Altos, CA 940221069. Office phone: 8663624246.
What is Dr. Karthikeyan Viswanathan's NPI?
Dr. Karthikeyan Viswanathan's National Provider Identifier (NPI) is 1396128336, issued by NPPES.
Does Dr. Karthikeyan Viswanathan accept Medicare assignment?
Yes. Dr. Karthikeyan Viswanathan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Karthikeyan Viswanathan commonly perform?
Top Medicare-reported procedures in 2023: Hemoglobin a1c level (HCPCS 83036); Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count (HCPCS 85025); Blood test, comprehensive group of blood chemicals (HCPCS 80053). Source: CMS Medicare Physician & Other Practitioners file.