Donald Widder
Family Medicine Physician · Martinez, CA
Donald Widder is a family medicine physician with a practice address in Martinez, California, and NPI 1033287529, issued on Dec 1, 2006. Check the license (California G55185, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Donald Widder
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- G55185 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2500 Alhambra Ave, Martinez, CA 94553
- Phone
- (925) 370-5110
- Enumerated
- Dec 1, 2006
- Record last updated
- May 21, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (925) 370-5142
- Medicare enrollment
- Enrolled (PECOS I20101228000853); accepts Medicare assignment
- Medical or professional school
- Stanford University School Of Medicine, 1975
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →
Also registered at 2500 Alhambra Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Pyra Aarden, MDEmergency Medicine Physician1417058199
- Zohaib AbbasiPsychiatry Physician1013392224
- Lolita AdonaFamily Nurse Practitioner1821110925
- Namita AgarwalPediatrics Physician1467626341
- Edward AgyekumDentist1124196696
- Abid Ahmed, M.D.Internal Medicine Physician1346531001
Verify Donald Widder in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G55185Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
The practice group's MIPS final score for 2023 (Medicare payment program): 95.9 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
- Modesto Radiological Medical Group IncModesto, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Donald Widder among 17,133 family medicine physician records in California
Donald Widder is one of 17,133 family 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 6% of them.
- NPI issued2006 · 6% of these records are older, 59% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated1975 · median 2005 among the 10,652 with a school on file
- Record last updated2013 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
191 family medicine physician records list a practice address in Martinez
They are 191 of the 1,816 NPPES records with a practice address in Martinez, and 17,133 family medicine physician records in California.
All 17,133 in California → Every provider in Martinez → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Melodie Armstrong, MDMartinez, CA 945531093821779
- Philipp Bannwart, M.D.Martinez, CA 945531194828491
- Fred Beck, MDMartinez, CA 945531447348891
- Kenneth Brooks, MDMartinez, CA 945531528009685
- Scott Carter, M.D.Martinez, CA 945531306820980
- Christopher Farnitano, MDMartinez, CA 945531770673832
- David Hearst, MDMartinez, CA 945531770670531
- Stephen Kalkstein, MDMartinez, CA 945531356438113
Common questions
What is Donald Widder's NPI number?
Donald Widder's National Provider Identifier (NPI) is 1033287529, issued on Dec 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Donald Widder located?
The NPPES record lists a practice address at 2500 Alhambra Ave, Martinez, CA, 94553. Phone: (925) 370-5110. Providers update this record themselves, so call before visiting.
How can I verify Donald Widder's license?
NPPES lists California license number G55185, 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.
What is Donald Widder's MIPS final score?
The 2023 MIPS final score is 95.9 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.