Quick answers
- Where does Karthikeyan Viswanathan see patients?
- Medicare's clinician data lists 4 practice locations, including Arcata, CA, Palo Alto, CA and Mobile, AL. Call before your visit to confirm the address.
- What is Karthikeyan Viswanathan's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Karthikeyan Viswanathan accept Medicare assignment?
- Medicare's clinician data says Karthikeyan Viswanathan may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is Karthikeyan Viswanathan's NPI number?
- 1396128336. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Karthikeyan Viswanathan is enrolled with Medicare (CMS data updated 2026-10-02).
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Arcata
Clinicians with the same Medicare primary specialty in Arcata, CA — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 2014 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1396128336 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians