William M. Mills, M.D.
Emergency Medicine Physician · Walnut Creek, CA
William M. Mills, M.D. is an emergency medicine physician with a practice address in Walnut Creek, California, and NPI 1497779300, issued on Jul 26, 2006. Check the license (California A62432, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William M. Mills
- Credential
- M.D.
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A62432 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1601 Ygnacio Valley RD, Walnut Creek, CA 94598
- Phone
- (925) 939-3000
- Enumerated
- Jul 26, 2006
- Record last updated
- Oct 26, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicaid ID
- 00A624320 CA
- Medicare enrollment
- Enrolled (PECOS I20080512000692); accepts Medicare assignment
- Medical or professional school
- Baylor College Of Medicine, 1993
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 1601 Ygnacio Valley RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Christine Abboud, D.O.Anesthesiology Physician1174901508
- Amy Aiyegbusi, IBCLCLactation Consultant (Registered Nurse)1275204067
- Alina AndradePhysician Assistant1114416773
- Radhika Annadata, MDAnesthesiology Physician1255379624
- Kirkman Beckwith, MDAnesthesiology Physician1073551057
- Stacie Bennett, MDNeonatal-Perinatal Medicine Physician1982660080
Verify William M. Mills in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A62432Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
10% fewer Medicare Part D claims than the average emergency medicine physician in 2024
204 Medicare Part D claims for 140 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 18 claims were for opioids.
Most prescribed
- Cephalexin19 claims
- Hydrocodone-Acetaminophen15 claims
- Ondansetron Odt12 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).
Industry payments in 2024: $50.33
1 payment: food and beverage; the largest payer was Globus Medical, Inc. The 12,335 providers of this specialty with any payment received $953.79 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through 2 group practices
- Cep America - CaliforniaConcord, CA
- Eastern Plumas Health Care DistrictPortola, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William M. Mills among 7,751 emergency medicine physician records in California
William M. Mills, M.D. 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 2006, is newer than 4% of them.
- NPI issued2006 · 4% of these records are older, 60% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated1993 · median 2011 among the 4,560 with a school on file
- Record last updated2007 · 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).
95 emergency medicine physician records list a practice address in Walnut Creek
They are 95 of the 6,170 NPPES records with a practice address in Walnut Creek, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Walnut Creek → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- David Birdsall, M.D.Walnut Creek, CA 945981164445615
- Daniel Buhler, M.D.Walnut Creek, CA 945981710908983
- Timothy Drazek, M.D.Walnut Creek, CA 945981336155795
- Paul Freitas, M.D.Walnut Creek, CA 945981558385641
- Alice Hunter, M.D.Walnut Creek, CA 945981023032125
- Malcolm Johnson, MDWalnut Creek, CA 945981003830316
- Andrew Kives, M.D.Walnut Creek, CA 945981972524007
- Theodore Kloth, M.D.Walnut Creek, CA 945981043234065
Common questions
What is William M. Mills, M.D.'s NPI number?
William M. Mills, M.D.'s National Provider Identifier (NPI) is 1497779300, issued on Jul 26, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William M. Mills, M.D. located?
The NPPES record lists a practice address at 1601 Ygnacio Valley RD, Walnut Creek, CA, 94598. Phone: (925) 939-3000. Providers update this record themselves, so call before visiting.
How can I verify William M. Mills, M.D.'s license?
NPPES lists California license number A62432, 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 M. Mills, M.D. prescribe under Medicare Part D?
In 2024, William M. Mills, M.D. had 204 Medicare Part D claims for 140 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
What is William M. Mills, M.D.'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.