William S. Clark, DO
Emergency Medicine Physician · Escalon, CA
William S. Clark, DO is an emergency medicine physician with a practice address in Escalon, California, and NPI 1770690430, issued on Aug 25, 2006. Check the license (California 20A8748, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William S. Clark
- Credential
- DO
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License numbers
- 20A8748 CA
02002521A IN
Self-reported in NPPES; status is on the state search - Practice location
- 1631 4TH St, Escalon, CA 95320
- Phone
- (209) 838-3434
- Enumerated
- Aug 25, 2006
- Record last updated
- May 12, 2022
- Medicaid ID
- 00AX87480 CA
- Medicare enrollment
- Enrolled (PECOS I20041001000742); accepts Medicare assignment
- Medical or professional school
- Chicago College Of Osteopathy, 2000
- Entity
- Type 1 · individual
Verify William S. Clark in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 20A8748Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
38% more Medicare Part D claims than the average emergency medicine physician in 2024
311 Medicare Part D claims for 197 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 31 claims were for opioids.
Most prescribed
- Levofloxacin30 claims
- Hydrocodone-Acetaminophen28 claims
- Cephalexin26 claims
- Ondansetron Odt26 claims
- Prednisone19 claims
- Sulfamethoxazole-Trimethoprim12 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): 94.6 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 3 group practices
- Cep America - CaliforniaSalinas, CA
- Erx Plus Professional CorporationMariposa, CA
- Premier Health PartnersMariposa, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
1 emergency medicine physician records list a practice address in Escalon
They are 1 of the 50 NPPES records with a practice address in Escalon, and 7,751 emergency medicine physician records in California.
Other emergency medicine physician records in California
- Cooper Aakhus, MDStanford, CA1194351007
- Pyra Aarden, MDMartinez, CA1417058199
- Neal Aaron, D.O.Encinitas, CA1114283520
- Eric AaserudeWalnut Creek, CA1811491194
- Nader Abas, MDBarstow, CA1346288305
- Michael Abbo, MDNovato, CA1205819042
- Daniel Abbott, MDFullerton, CA1518907864
- Paul-Andre Abboud, M.D.Oakland, CA1710065503
- Mostafa Abdel-Hamid, MDStanford, CA1457918740
- Ashraf Abdel-KerimChino, CA1396961538
Common questions
What is William S. Clark, DO's NPI number?
William S. Clark, DO's National Provider Identifier (NPI) is 1770690430, issued on Aug 25, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William S. Clark, DO located?
The NPPES record lists a practice address at 1631 4TH St, Escalon, CA, 95320. Phone: (209) 838-3434. Providers update this record themselves, so call before visiting.
How can I verify William S. Clark, DO's license?
NPPES lists California license number 20A8748, 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 S. Clark, DO prescribe under Medicare Part D?
In 2024, William S. Clark, DO had 311 Medicare Part D claims for 197 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
What is William S. Clark, DO's MIPS final score?
The 2023 MIPS final score is 94.6 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.