Stephen Loo, DO
NPI 1174607162 · Internal Medicine Physician · San Rafael, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Stephen Loo, DO is a Internal Medicine Physician provider in San Rafael, CA (NPI 1174607162).
Provider details
- NPI number
- 1174607162
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Male
- Sole proprietor
- No
- License
- 20A5422 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
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
Mailing address
Registry dates
- Enumerated
- 2006-10-25
- Last updated
- 2021-12-13
Frequently asked questions
- What is Stephen Loo's NPI number?
- Stephen Loo's National Provider Identifier (NPI) is 1174607162, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Stephen Loo's specialty?
- Stephen Loo is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Stephen Loo located?
- Stephen Loo's practice location on file with NPPES is 99 Montecillo Rd, San Rafael, CA 94903-3308.
- What is Stephen Loo's phone number?
- The practice phone number listed in the NPPES registry for Stephen Loo is (415) 444-2000.
- Does Stephen Loo accept Medicare?
- Stephen Loo is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Stephen Loo's NPI active?
- Yes — Stephen Loo's NPI (1174607162) is active in the NPPES registry as of the last update on 2021-12-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.