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Bryn Duffy, MD
NPI 1235243775 · Internal Medicine Physician · San Rafael, CA
Bryn Duffy, MD is a Internal Medicine Physician provider in San Rafael, CA (NPI 1235243775).
Provider details
- NPI number
- 1235243775
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- A110571 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
Detailed profile(90/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
16 Bolanos Dr
San Rafael, CA 94903-3103
Phone: (415) 306-1560
Street-level locationGet directions
Mailing address
80 Ramblewood Dr
North Chili, NY 14514-1033
Registry dates
- Enumerated
- 2006-08-19
- Last updated
- 2010-02-01
Frequently asked questions
- What is Bryn Duffy's NPI number?
- Bryn Duffy's National Provider Identifier (NPI) is 1235243775, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Bryn Duffy's specialty?
- Bryn Duffy is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Bryn Duffy located?
- Bryn Duffy's practice location on file with NPPES is 16 Bolanos Dr, San Rafael, CA 94903-3103.
- What is Bryn Duffy's phone number?
- The practice phone number listed in the NPPES registry for Bryn Duffy is (415) 306-1560.
- Is Bryn Duffy's NPI active?
- Yes — Bryn Duffy's NPI (1235243775) is active in the NPPES registry as of the last update on 2010-02-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.