Are you William N. Hamstra, D.O.? This profile is yours to edit: update your address, phone, photo and services.

Edit this profile

Physician Profile

William N. Hamstra, D.O.

Is this you? Edit this profile

At a glance

About Dr. Hamstra

Based in San Ramon, CA, William N. Hamstra, D.O. is listed in the NPI registry under surgery. William graduated from Oklahoma State University College of Osteopathic Medicine in 1986. NPI 1306835723 identifies this record in the national registry.

Factual summary compiled by Guide.md from public records; not written by this provider.

Specialty

Surgery (Primary)

Credentials & Licensing

CA · Osteopathic Physician and Surgeon 20AOsteopathic Medical Board of California
No. 5413CurrentExpires Dec 31, 2026Since 1987
CA licenceAs reported to the NPI registry
No. 20A5413As reported
NPINational Provider Identifier
1306835723Issued 2005

Snapshot · verify with the board ↗

Medicare information

Accepts Medicare assignmentYes
Medicare opt-outNo
Can order and refer in MedicareYes

Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.

Common questions

What kind of doctor is William N. Hamstra?

William N. Hamstra is a general surgeon in San Ramon, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Surgery”.

NPI registry

What is William N. Hamstra's address?

William N. Hamstra is listed at 2305 Camino Ramon Suite 217, San Ramon, CA 94583. Addresses come from the NPI registry and can lag a move, so confirm before travelling.

NPI registry

How can I make an appointment with William N. Hamstra?

The number on file is (925) 447-0660. Contact the office directly to confirm availability and scheduling.

NPI registry

What is the NPI for William N. Hamstra?

William N. Hamstra's National Provider Identifier is 1306835723. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.

NPI registry

Where did William N. Hamstra train?

William N. Hamstra attended Oklahoma State University College of Osteopathic Medicine, graduating in 1986. This comes from the CMS National Downloadable File.

CMS public data

How much experience does William N. Hamstra have?

William N. Hamstra has 40 years experience. Calculated from a graduation year of 1986, reported in the CMS National Downloadable File.

CMS public data

Is William N. Hamstra's profile verified?

Not yet. This profile is built from public federal data and has not been confirmed by William N. Hamstra. If this is you, claiming it is free.

Guide.md

Guide.md listings do not constitute medical advice or an endorsement.