Doug John Williamson, MD
Emergency Medicine Physician · Riverside, CA
Doug John Williamson, MD is an emergency medicine physician with a practice address in Riverside, California, and NPI 1033267067, issued on Jan 8, 2007. Check the license (California A79642, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Doug John Williamson
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A79642 CA
Self-reported in NPPES; status is on the state search - Practice location
- 10800 Magnolia Ave, Riverside, CA 92505
- Phone
- (909) 353-2000
- Enumerated
- Jan 8, 2007
- Record last updated
- Nov 29, 2021 (not updated in 5 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 10800 Magnolia Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Doug John Williamson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A79642Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
59% fewer Medicare Part D claims than the average emergency medicine physician in 2024
93 Medicare Part D claims for 60 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 14 claims were for opioids.
Most prescribed
- Cephalexin16 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.
Doug John Williamson among 7,751 emergency medicine physician records in California
Doug John Williamson, 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. Its NPI, issued in 2007, is newer than 40% of them.
- NPI issued2007 · 40% of these records are older, 50% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileNo · 59% of these records are
- Record last updated2021 · 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).
Emergency Medicine Physician providers in California
There are 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Riverside → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Oscar Benitez, MDRiverside, CA 925051710035696
- Barbara Blasko, MDRiverside, CA 925051689741597
- Richard Clinton, M.D.Riverside, CA 925051912117813
- Michael Cordeiro, M.D.Riverside, CA 925051902048473
- Stephen Ferrall, MDRiverside, CA 925051487721296
- Franklin Gbenedio, DORiverside, CA 925051285793943
- Bret Kilker, M.D.Riverside, CA 925051447494497
- Bruce Kim, MDRiverside, CA 925051699834259
Common questions
What is Doug John Williamson, MD's NPI number?
Doug John Williamson, MD's National Provider Identifier (NPI) is 1033267067, issued on Jan 8, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Doug John Williamson, MD located?
The NPPES record lists a practice address at 10800 Magnolia Ave, Riverside, CA, 92505. Phone: (909) 353-2000. Providers update this record themselves, so call before visiting.
How can I verify Doug John Williamson, MD's license?
NPPES lists California license number A79642, 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 Doug John Williamson, MD prescribe under Medicare Part D?
In 2024, Doug John Williamson, MD had 93 Medicare Part D claims for 60 beneficiaries; the average among emergency medicine physician prescribers was 226. 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.