Katherine Williams, M.D.
Internal Medicine Physician · Saint Helena, CA
Katherine Williams, M.D. is an internal medicine physician with a practice address in Saint Helena, California, and NPI 1710371463, issued on Mar 20, 2015. Check the license (California G57420, as entered in NPPES) on the Medical Board of California; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Katherine Williams
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G57420 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2800 St. Helena Highway North, Saint Helena, CA 94574
- Phone
- (707) 758-5936
- Enumerated
- Mar 20, 2015
- Record last updated
- Mar 20, 2015 (not updated in 11 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20260309003307); may accept Medicare assignment
- Medical or professional school
- University Of California, San Francisco School Of Medicine, 1984
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Verify Katherine Williams in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G57420Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Katherine Williams among 17,696 internal medicine physician records in California
Katherine Williams, M.D. is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 2015, is newer than 76% of them.
- NPI issued2015 · 76% of these records are older, 21% newer
- In a Medicare fileNo · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1984 · median 2004 among the 11,065 with a school on file
- Record last updated2015 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
11 internal medicine physician records list a practice address in Saint Helena
They are 11 of the 232 NPPES records with a practice address in Saint Helena, and 17,696 internal medicine physician records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 17,696 in California → Every provider in Saint Helena → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sahiba Bajwa, MDSaint Helena, CA 945741346869567
- Matthew Corvo, MDSaint Helena, CA 945741265811475
- Susan Gamble, M.D.Saint Helena, CA 945741790950079
- Leah Grabenauer, MDSaint Helena, CA 945741760740385
- John Hart, MDSaint Helena, CA 945741104904945
- Hirofumi Hashimoto, MDSaint Helena, CA 945741104812585
- Arun Hatwalkar, MDSaint Helena, CA 945741689600090
- Padmaja Manyam, M.D.Saint Helena, CA 945741679882500
Common questions
What is Katherine Williams, M.D.'s NPI number?
Katherine Williams, M.D.'s National Provider Identifier (NPI) is 1710371463, issued on Mar 20, 2015. An NPI identifies a provider in billing; it is not a license.
Where is Katherine Williams, M.D. located?
The NPPES record lists a practice address at 2800 St. Helena Highway North, Saint Helena, CA, 94574. Phone: (707) 758-5936. Providers update this record themselves, so call before visiting.
How can I verify Katherine Williams, M.D.'s license?
NPPES lists California license number G57420, 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.