Mathias Masem, M.D.
NPI 1457371643 · Specialist · Oakland, CA
Enrolled with Medicare as Dme Supplier - Physician - General Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mathias Masem, M.D. is a Specialist organization in Oakland, CA (NPI 1457371643).
Provider details
- NPI number
- 1457371643
- Entity type
- Organization
- Primary specialty
- SpecialistOther Service Providers
- Organization subpart
- No
- Authorized official
- Mathias Masem, Sole Practioner(510) 763-0709
- License
- G34134 (CA)
Specialties & taxonomies
Other Service Providers
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
- 2006-07-20
- Last updated
- 2020-08-22
Frequently asked questions
- What is Mathias Masem, M.D.'s NPI number?
- Mathias Masem, M.D.'s National Provider Identifier (NPI) is 1457371643, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Mathias Masem, M.D.?
- Mathias Masem, M.D. is classified in the NPPES registry as Specialist (Other Service Providers).
- Where is Mathias Masem, M.D. located?
- Mathias Masem, M.D.'s practice location on file with NPPES is 80 Grand Ave.,, Oakland, CA 94612.
- What is Mathias Masem, M.D.'s phone number?
- The practice phone number listed in the NPPES registry for Mathias Masem, M.D. is (510) 763-0709.
- Does Mathias Masem, M.D. accept Medicare?
- Mathias Masem, M.D. is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Who is the authorized official for Mathias Masem, M.D.?
- The authorized official listed on Mathias Masem, M.D.'s NPPES record is Mathias Masem, Sole Practioner. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Mathias Masem, M.D.'s NPI active?
- Yes — Mathias Masem, M.D.'s NPI (1457371643) is active in the NPPES registry as of the last update on 2020-08-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.