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

William M. Greif, MD

Individual provider Surgery Physician · NPI 1013095108

William M. Greif, MD is a General Surgery in Walnut Creek, California. Graduated from Stanford University School of Medicine in 1993, 33 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
33
Trained at
Stanford University School of Medicine
Licensed in
CA
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1425 S Main St
Walnut Creek, CA 94596-5318
Phone: (925) 295-4000
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Surgery Physician (primary) Taxonomy 208600000X · Licence G85813 (CA)

Record details

NPI number1013095108
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedNovember 2, 2006
Last updated in NPPESDecember 13, 2021
Mailing address1800 Harrison St Fl 7, Oakland, CA 94612-3466

Medicare enrollment

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

Medicare specialtyGENERAL SURGERY
Also practisesSURGICAL ONCOLOGY, THORACIC SURGERY, VASCULAR SURGERY
Medical schoolSTANFORD UNIVERSITY SCHOOL OF MEDICINE
Graduated 1993 (33 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare

Other providers in Walnut Creek