William M Mills, M.D.

Individual provider Active NPI Emergency Medicine Physician · Walnut Creek, CA

NPI 1497779300 · NPPES record last updated Oct 26, 2007

Key facts

NPI
1497779300
Entity type
Individual (NPI type 1)
Primary specialty
Emergency Medicine Physician 207P00000X
License
A62432 (CA)
Practice address
1601 Ygnacio Valley Rd
Walnut Creek, CA 94598-3122
Phone
(925) 939-3000
NPI assigned
Jul 26, 2006
Sex
Male
Sole proprietor
No

Organizations & group practices 15

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

Hospital & facility affiliations 4

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

Medicare Care Compare profile

Specialty
Emergency Medicine
Education
Baylor College of Medicine, 1993
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Group practices
Cep America - California (1,278 clinicians)
Eastern Plumas Health Care District (31 clinicians)

Practice addresses (Care Compare)

2540 E St
Concord, CA 94520-1906
Phone (929) 682-8200

480 1St Ave
Portola, CA 96122-9405
Phone (530) 832-6600

500 1St Ave
Portola, CA 96122-9406

Hospital & facility affiliations

  • John Muir Medical Center - Walnut Creek Campus Hospital · Walnut Creek, CA · CCN 050180
  • John Muir Medical Center - Concord Campus Hospital · Concord, CA · CCN 050496
  • Eastern Plumas Hospital - Portola Campus Hospital · Portola, CA · CCN 051300

Merit-based Incentive Payment System (MIPS)

Final score
96.69 of 100 (group)
Quality
90
Improvement activities
40
Cost
78.43

Medicare participation

Medicare fee-for-service enrollment
Enrolled in CA
Eligible to order & refer
Part B services: Yes · DME: Yes · Home health: Yes · Power mobility devices: Yes · Hospice: Yes

Medicare enrollment records

Enrollment IDStateProvider typePAC IDDetails
I20080512000692 CA Practitioner - Emergency Medicine 3779662069 Reassigns benefits to 3 organizations

National Provider Directory

Medicare enrollment (NPD)
Yes
Credentials
Doctor of Medicine

State licenses

LicenseStateTypeSpecialty
A62432CAMDEmergency Medicine Physician

Practice roles

OrganizationSpecialtyStatusNew patients
Eastern Plumas Health Care District Current
since Dec 5, 2025
Accepting new patients
Cep America-California Emergency Medicine Current
since Nov 1, 1999
Accepting new patients
Cep America - California Emergency Medicine Current
since Nov 1, 1999
Accepting new patients
Eastern Plumas Health Care Home Health Current
since Jan 29, 2018
Accepting new patients
Cep America - California Emergency Medicine Current Accepting new patients
Eastern Plumas Health Care District Current
since Jan 29, 2018
Accepting new patients
Berkeley Emergency Medical Group, Inc. Emergency Medicine Past
since Jan 22, 2023
Accepting new patients
Berkeley Emergency Medical Group, Inc. Emergency Medicine Past
since Jan 22, 2023
Accepting new patients

Locations

2540 East St
Concord, CA 94520
Phone (925) 674-2228

2100 Powell St
Ste 900
Emeryville, CA 94608
Phone (510) 350-2777

1601 Cummins Dr
Ste D
Modesto, CA 95358
Phone (510) 851-7423

350 Hawthorne Ave
Oakland, CA 94609
Phone (510) 655-4000

480 1st Ave
Portola, CA 96122
Phone (530) 832-6600

500 1st Ave
Portola, CA 96122
Phone (530) 832-4277

4445 Magnolia Ave
Riverside, CA 92501
Phone (800) 498-7156

450 Stanyan St
San Francisco, CA 94117
Phone (415) 668-1000

1601 Ygnacio Valley Rd
Walnut Creek, CA 94598
Phone (925) 295-1545

Specialties & licenses

Specialty (taxonomy)CodeLicenseStatePrimary
Emergency Medicine Physician 207P00000X A62432 CA Yes

Addresses

Primary practice location

1601 Ygnacio Valley Rd
Walnut Creek, CA 94598-3122

Mailing address

2100 Powell St
Suite 900
Emeryville, CA 94608-1826
Phone (510) 350-2600

Other identifiers

IdentifierTypeStateIssuer
00A624320MedicaidCA

Other providers in Walnut Creek, CA

All providers in Walnut Creek, CA · Emergency Medicine Physician in California

Sources for this page

Verify at the official NPI Registry.