Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

William Norman Hamstra, DO

Individual provider Surgery Physician · NPI 1306835723

William Norman Hamstra, DO practises General Surgery in San Ramon, California. Graduated from Oklahoma State University College of Osteopathic Medicine in 1986, 40 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
40
Trained at
Oklahoma State University College of Osteopathic Medicine
Licensed in
CA
In the registry since
2005
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

2305 Camino Ramon Ste 217
San Ramon, CA 94583-1396
Phone: (925) 447-0660
Fax: (925) 443-7506
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

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

Specialties & licences

Surgery Physician (primary) Taxonomy 208600000X · Licence 20A5413 (CA)

Record details

NPI number1306835723
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorYes
NPI enumeratedOctober 18, 2005
Last updated in NPPESFebruary 11, 2022

Medicare enrollment

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

Medicare specialtyGENERAL SURGERY
Medical schoolOKLAHOMA STATE UNIVERSITY COLLEGE OF OSTEOPATHIC MEDICINE
Graduated 1986 (40 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Melanoma (skin cancer) excision 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Colleagues at Permanente Medical Group Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 10941 clinicians in the practice; 12 are shown here.

Other providers in San Ramon