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

Dr. John Nicholas Diana, MD

Individual provider Adult Reconstructive Orthopaedic Surgery Physician · NPI 1649297540

Dr. John Nicholas Diana, MD is an Orthopedic Surgery in Napa, California. Graduated from Indiana University School of Medicine in 1996, 30 years ago. Practices with St Helena Hospital, a 86-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
30
Trained at
Indiana University School of Medicine
Licensed in
CA
In the registry since
2006
Specialties on file
3
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

3273 Claremont Way Ste 100
Napa, CA 94558-3306
Phone: (707) 254-7117
Fax: (707) 265-6435
Show map & directions

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

Specialties & licences

Adult Reconstructive Orthopaedic Surgery Physician (primary) Taxonomy 207XS0114X · Licence A87859 (CA)
Sports Medicine (Orthopaedic Surgery) Physician Taxonomy 207XX0005X · Licence A87859 (CA)
Orthopaedic Trauma Physician Taxonomy 207XX0801X · Licence A87859 (CA)

Record details

NPI number1649297540
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 16, 2006
Last updated in NPPESOctober 22, 2014

Medicare enrollment

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

Medicare specialtyORTHOPEDIC SURGERY
Medical schoolINDIANA UNIVERSITY SCHOOL OF MEDICINE
Graduated 1996 (30 years in practice)
Group practice St. Helena Hospital — 86 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare