John O'Brien Clarke III, M.D.
NPI 1467539643ActiveIndividual· Internal Medicine, Gastroenterology· Palo Alto, CA
Internal Medicine, Gastroenterology (M.D.) in Palo Alto, California, trained at University of Missouri, Columbia School of Medicine (class of 1999). Their prescriptions cost Medicare Part D more than their services did: $282,842 for 901 claims, against $122,769 paid for services in 2024. Phathom Pharmaceuticals, Inc. was the largest of 2 companies reporting payments in 2025, $129.92 in all, mostly food and beverage.
Overview
| NPI | 1467539643 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Nov 1, 2006 |
| Last updated in NPPES | Apr 28, 2024 |
| Certified by provider | Apr 28, 2024 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | C143081 | CA |
| Internal Medicine | 207R00000X | D58832 | MD |
| Internal Medicine | 207R00000X | C143081 | CA |
| Internal Medicine, Gastroenterology | 207RG0100X | D58832 | MD |
| Hospitalist | 208M00000X | D58832 | MD |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 593 |
|---|---|
| Services billed | 1,476 across 53 procedure codes |
| Paid by Medicare | $122,769 |
Part D prescriptions in 2024
| Prescriptions (claims) | 901 · 1,735 30-day fills |
|---|---|
| Patients | 244 |
| Total drug cost | $282,842 |
| Generic share | 75% of claims |
Education and affiliations
| Medical school | University of Missouri, Columbia School of Medicine |
|---|---|
| Graduation year | 1999 |
| Medicare specialty | Gastroenterology |
| Telehealth | Offers telehealth |
Medical group
- Stanford Health CareStanford, CA · 3,122 clinicians
Hospital affiliation
- Stanford Health CareStanford, CA
Industry payments (Open Payments)
- 2025$129.92 · 2 payments from 2 companies
- 2024$1,919 · 2 payments from 2 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Phathom Pharmaceuticals, Inc. | $100.47 | 1 |
| Mauna Kea Technologies, Inc. | $29.45 | 1 |
What the 2025 payments were for
- Food and Beverage$129.92 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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