Michael Mason, MD
NPI 1215011200 · Internal Medicine Physician · San Rafael, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Mason, MD is a Internal Medicine Physician provider in San Rafael, CA (NPI 1215011200).
Provider details
- NPI number
- 1215011200
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A62372 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 109 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 661 | 225 |
| Lisinopril | 255 | 89 |
| Amlodipine Besylate | 240 | 82 |
| Levothyroxine Sodium | 204 | 66 |
| Tamsulosin Hcl | 170 | 57 |
| Famotidine | 164 | 48 |
| Atenolol | 158 | 51 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-10-25
- Last updated
- 2021-12-13
Frequently asked questions
- What is Michael Mason's NPI number?
- Michael Mason's National Provider Identifier (NPI) is 1215011200, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Mason's specialty?
- Michael Mason is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Mason located?
- Michael Mason's practice location on file with NPPES is 99 Montecillo Rd, San Rafael, CA 94903-3308.
- What is Michael Mason's phone number?
- The practice phone number listed in the NPPES registry for Michael Mason is (415) 444-2000.
- Does Michael Mason accept Medicare?
- Michael Mason is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Mason's NPI active?
- Yes — Michael Mason's NPI (1215011200) 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.