Robert R. Williams, M.D.
Internal Medicine Physician · Tracy, CA
Robert R. Williams, M.D. is an internal medicine physician with a practice address in Tracy, California, and NPI 1184682254, issued on May 1, 2006. Check the license (California G62642, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Robert R. Williams
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G62642 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2151 W Grant Line RD, Tracy, CA 95377
- Phone
- (209) 832-0535
- Enumerated
- May 1, 2006
- Record last updated
- Feb 25, 2011 (not updated in 15 years: call before relying on the address or phone)
- Medicaid ID
- 00G626420 CA
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 2151 W Grant Line RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Robert R. Williams in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G62642Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
96% fewer Medicare Part D claims than the average internal medicine physician in 2024
135 Medicare Part D claims for 42 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Levothyroxine Sodium12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Robert R. Williams among 17,696 internal medicine physician records in California
Robert R. 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. Its NPI, issued in 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileNo · 63% of these records are
- Record last updated2011 · 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).
27 internal medicine physician records list a practice address in Tracy
They are 27 of the 1,864 NPPES records with a practice address in Tracy, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Tracy → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Usman Ali, M.D.Tracy, CA 953771154355832
- Sherry Han, MDTracy, CA 953771558433391
- Shaheen Jawahar, MDTracy, CA 953771982931598
- Rollie Rosete, MDTracy, CA 953771801838610
- Satvinder Sachdeva, MDTracy, CA 953771831277649
- James Stephen, MDTracy, CA 953771144308032
- Juan Vergara Saavedra, M.D.Tracy, CA 953771124295316
- Florence Wandisan-Rosete, MDTracy, CA 953771457396897
Common questions
What is Robert R. Williams, M.D.'s NPI number?
Robert R. Williams, M.D.'s National Provider Identifier (NPI) is 1184682254, issued on May 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Robert R. Williams, M.D. located?
The NPPES record lists a practice address at 2151 W Grant Line RD, Tracy, CA, 95377. Phone: (209) 832-0535. Providers update this record themselves, so call before visiting.
How can I verify Robert R. Williams, M.D.'s license?
NPPES lists California license number G62642, 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.
How much does Robert R. Williams, M.D. prescribe under Medicare Part D?
In 2024, Robert R. Williams, M.D. had 135 Medicare Part D claims for 42 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. 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.