Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Ravi Viswanathan, MD

Allergy Physician in Madison, WI · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1326084534

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Registry record

Entity type Individual (Type 1)

Name Dr. Ravi Viswanathan

Credential MD

Sex Male

Practice address 451 Junction Rd, Madison, WI, 53717

Phone (608) 263-6180

Fax (608) 890-6276

Enumeration date Jun 22, 2006

Last updated in NPPES Oct 26, 2021

Taxonomy & licenses

207RA0201X Allergy & Immunology (Internal Medicine) Physician Allopathic & Osteopathic Physicians · License 52208 (WI) Secondary

2080P0201X Pediatric Allergy/Immunology Physician Allopathic & Osteopathic Physicians · License 52208 (WI) Secondary

207KA0200X Allergy Physician Allopathic & Osteopathic Physicians · License 52208 (WI) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What is the NPI number for Ravi Viswanathan?

The National Provider Identifier (NPI) for Ravi Viswanathan is 1326084534, a Type 1 (individual) record in the CMS NPPES registry.

Where does Ravi Viswanathan practice?

The practice location on file with NPPES is in Madison, WI. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

Melinda Rose Nurse Practitioner · Madison, WI NPI 1174517320 Daniela Constantinescu Internal Medicine Physician · Madison, WI NPI 1033103940 Vidushi Sood Endocrinology, Diabetes & Metabolism Physician · Madison, WI NPI 1194712703 Anurag Soni Gastroenterology Physician · Madison, WI NPI 1215924816 Ann Hartman Physician Assistant · Madison, WI NPI 1043281454 Teresa Wolfe Medical Physician Assistant · Madison, WI NPI 1003889817 Christine Seroogy Pediatric Allergy/Immunology Physician · Madison, WI NPI 1053387704 Arnold Wald Gastroenterology Physician · Madison, WI NPI 1063488419

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2021-10-26.