David S. Duffy, M.D.
Emergency Medicine Physician · Greenbrae, CA
David S. Duffy, M.D. is an emergency medicine physician with a practice address in Greenbrae, California, and NPI 1861414203, issued on Jul 24, 2006. Check the license (California G71879, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- David S. Duffy
- Credential
- M.D.
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- G71879 CA
Self-reported in NPPES; status is on the state search - Practice location
- 250 Bon Air RD, Greenbrae, CA 94904
- Phone
- (415) 925-7000
- Enumerated
- Jul 24, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20080512000358); accepts Medicare assignment
- Medical or professional school
- Tufts University School Of Medicine, 1990
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 250 Bon Air RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Lisa Abrahams, MFTMarriage & Family Therapist1184738445
- Jory Adam, PA-CSurgical Physician Assistant1922269521
- Samuel Adams, MDHospitalist Physician1497785034
- Barbara Addleman, RNRegistered Nurse1053551267
- Linda Alexander, RNPsychiatric/Mental Health Registered Nurse1205589405
- Maxwell AlikinneyCounselor1538668728
Verify David S. Duffy in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G71879Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
53% fewer Medicare Part D claims than the average emergency medicine physician in 2024
106 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. 14 claims were for opioids.
Most prescribed
- Cephalexin18 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 one group practice
- Cep America - CaliforniaSan Francisco, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
David S. Duffy among 7,751 emergency medicine physician records in California
David S. Duffy, 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
- Graduated1990 · 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).
12 emergency medicine physician records list a practice address in Greenbrae
They are 12 of the 727 NPPES records with a practice address in Greenbrae, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Greenbrae → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Arthur Cohn, M.D.Greenbrae, CA 949041033137831
- Tami Gash-Kim, M.DGreenbrae, CA 949041164440848
- Lara Kulchycki, M.D.Greenbrae, CA 949041558317032
- Robert Riner, M.D.Greenbrae, CA 949041912929290
- Alan Spain, M.D.Greenbrae, CA 949041548282825
- Carl Spitzer, M.D.Greenbrae, CA 949041881612455
- Sean Tiret, MDGreenbrae, CA 949041770043119
- Katherine Tran, MDGreenbrae, CA 949041265992606
Common questions
What is David S. Duffy, M.D.'s NPI number?
David S. Duffy, M.D.'s National Provider Identifier (NPI) is 1861414203, issued on Jul 24, 2006. An NPI identifies a provider in billing; it is not a license.
Where is David S. Duffy, M.D. located?
The NPPES record lists a practice address at 250 Bon Air RD, Greenbrae, CA, 94904. Phone: (415) 925-7000. Providers update this record themselves, so call before visiting.
How can I verify David S. Duffy, M.D.'s license?
NPPES lists California license number G71879, 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 David S. Duffy, M.D. prescribe under Medicare Part D?
In 2024, David S. Duffy, M.D. had 106 Medicare Part D claims for 81 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
What is David S. Duffy, 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.