Mary Elizabeth Clark, M.D.
NPI 1225109770 · Gastroenterology Physician · San Francisco, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Elizabeth Clark, M.D. is a Gastroenterology Physician provider in San Francisco, CA (NPI 1225109770).
Provider details
- NPI number
- 1225109770
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- Yes
- License
- A98304 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 · 20 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 241 | 236 |
| Omeprazole | 81 | 41 |
| Pantoprazole Sodium | 65 | 24 |
| Famotidine | 32 | 14 |
| Esomeprazole Magnesium | 31 | 14 |
| Prucalopride Succinatebrand: Motegrity | 27 | — |
| Mesalamine | 26 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$43 across 2 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-13
- Last updated
- 2022-01-13
- Certified
- 2022-01-13
Frequently asked questions
- What is Mary Elizabeth Clark's NPI number?
- Mary Elizabeth Clark's National Provider Identifier (NPI) is 1225109770, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Elizabeth Clark's specialty?
- Mary Elizabeth Clark is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Mary Elizabeth Clark located?
- Mary Elizabeth Clark's practice location on file with NPPES is 2333 Buchanan St, San Francisco, CA 94115-1925.
- What is Mary Elizabeth Clark's phone number?
- The practice phone number listed in the NPPES registry for Mary Elizabeth Clark is (415) 644-5752.
- Does Mary Elizabeth Clark accept Medicare?
- Mary Elizabeth Clark is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Elizabeth Clark's NPI active?
- Yes — Mary Elizabeth Clark's NPI (1225109770) is active in the NPPES registry as of the last update on 2022-01-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.