William G. Keyser, MD
Emergency Medicine Physician · Sonoma, CA
William G. Keyser, MD is an emergency medicine physician with a practice address in Sonoma, California, and NPI 1306859194, issued on Aug 14, 2006. Check the license (California C32412, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- William G. Keyser
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- C32412 CA
Self-reported in NPPES; status is on the state search - Practice location
- 347 Andrieux Street, Sonoma, CA 95476
- Phone
- (707) 935-5100
- Enumerated
- Aug 14, 2006
- Record last updated
- Jul 2, 2008 (not updated in 18 years: call before relying on the address or phone)
- Medicaid ID
- 00C324120 CA
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 347 Andrieux Street
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jay Goldberg, MDEmergency Medicine Physician1225141971
- Stephen Kahn, MDEmergency Medicine Physician1962515262
- Mark Wills, MDEmergency Medicine Physician1063525715
Verify William G. Keyser in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C32412Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
William G. Keyser among 7,751 emergency medicine physician records in California
William G. Keyser, MD is one of 7,751 emergency medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 4% of them.
- NPI issued2006 · 4% of these records are older, 60% newer
- In a Medicare fileNo · 81% of these records are
- In the CMS Doctors and Clinicians fileNo · 59% of these records are
- Record last updated2008 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
8 emergency medicine physician records list a practice address in Sonoma
They are 8 of the 395 NPPES records with a practice address in Sonoma, and 7,751 emergency medicine physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 7,751 in California → Every provider in Sonoma → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Erick French, MDSonoma, CA 954761649206806
- Jay Goldberg, MDSonoma, CA 954761225141971
- Leslie Graham, M.D.Sonoma, CA 954761841463346
- Stephen Kahn, MDSonoma, CA 954761962515262
- Robert Petty, DOSonoma, CA 954761497795496
- Nicolas Sawyer, M.D.Sonoma, CA 954761033470760
- Mark Wills, MDSonoma, CA 954761063525715
- Michele Borgeson, MDSebastopol, CA 954721396700936
Common questions
What is William G. Keyser, MD's NPI number?
William G. Keyser, MD's National Provider Identifier (NPI) is 1306859194, issued on Aug 14, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William G. Keyser, MD located?
The NPPES record lists a practice address at 347 Andrieux Street, Sonoma, CA, 95476. Phone: (707) 935-5100. Providers update this record themselves, so call before visiting.
How can I verify William G. Keyser, MD's license?
NPPES lists California license number C32412, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.