William Michael Downes, MD
Emergency Medicine Physician · Loma Linda, CA
William Michael Downes, MD is an emergency medicine physician with a practice address in Loma Linda, California, and NPI 1912494808, issued on Apr 17, 2018. Check the license (California A163443, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William Michael Downes
- Credential
- MD
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A163443 CA
Self-reported in NPPES; status is on the state search - Practice location
- 11234 Anderson St, A890, Loma Linda, CA 92354
- Phone
- (909) 558-4085
- Enumerated
- Apr 17, 2018
- Record last updated
- Aug 12, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20210615003192); accepts Medicare assignment
- Medical or professional school
- Loma Linda University School Of Medicine, 2018
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 11234 Anderson St, A890
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Cory ToomasianEmergency Medicine Physician1790218089
Verify William Michael Downes in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A163443Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
48% fewer Medicare Part D claims than the average emergency medicine physician in 2024
118 Medicare Part D claims for 81 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D.
Most prescribed
- Cephalexin12 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 85.2 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Faculty Physicians And Surgeons OF LlusmLoma Linda, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Michael Downes among 7,751 emergency medicine physician records in California
William Michael Downes, 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 2018, is newer than 81% of them.
- NPI issued2018 · 81% of these records are older, 15% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2018 · median 2011 among the 4,560 with a school on file
- 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).
168 emergency medicine physician records list a practice address in Loma Linda
They are 168 of the 4,863 NPPES records with a practice address in Loma Linda, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Loma Linda → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Robert Bassler, M.D.Loma Linda, CA 923541184675902
- Lance Brown, M.D.Loma Linda, CA 923541376562793
- Deepak Chandwani, M.D.Loma Linda, CA 923541144264177
- Tony Chow, M.D.Loma Linda, CA 923541154340578
- Lynda Daniel-Underwood, M.D.Loma Linda, CA 923541063447241
- Jeff Grange, M.D.Loma Linda, CA 923541801815238
- Steven Green, M.D.Loma Linda, CA 923541619996048
- Gregory Guldner, M.D.Loma Linda, CA 923541932125523
Common questions
What is William Michael Downes, MD's NPI number?
William Michael Downes, MD's National Provider Identifier (NPI) is 1912494808, issued on Apr 17, 2018. An NPI identifies a provider in billing; it is not a license.
Where is William Michael Downes, MD located?
The NPPES record lists a practice address at 11234 Anderson St, A890, Loma Linda, CA, 92354. Phone: (909) 558-4085. Providers update this record themselves, so call before visiting.
How can I verify William Michael Downes, MD's license?
NPPES lists California license number A163443, 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 William Michael Downes, MD prescribe under Medicare Part D?
In 2024, William Michael Downes, MD had 118 Medicare Part D claims for 81 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
What is William Michael Downes, MD's MIPS final score?
The 2023 MIPS final score is 85.2 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.