Michael Masterson, M.D.
NPI 1649240052 · Medical Oncology Physician · Westlake Village, CA
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Masterson, M.D. is a Medical Oncology Physician provider in Westlake Village, CA (NPI 1649240052).
Provider details
- NPI number
- 1649240052
- Entity type
- Individual
- Primary specialty
- Medical Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G27552 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 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
- 2006-01-26
- Last updated
- 2015-02-03
Frequently asked questions
- What is Michael Masterson's NPI number?
- Michael Masterson's National Provider Identifier (NPI) is 1649240052, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Masterson's specialty?
- Michael Masterson is listed in the NPPES registry with a primary specialty of Medical Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Masterson located?
- Michael Masterson's practice location on file with NPPES is 1250 La Venta, Westlake Village, CA 91361.
- What is Michael Masterson's phone number?
- The practice phone number listed in the NPPES registry for Michael Masterson is (805) 496-5153.
- Does Michael Masterson accept Medicare?
- Michael Masterson is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Masterson's NPI active?
- Yes — Michael Masterson's NPI (1649240052) is active in the NPPES registry as of the last update on 2015-02-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.