Dennis Y. Chan, M. D.
Internal Medicine, Gastroenterology (M. D.) with Global Gastroenterology Group Inc, practicing in Monterey Park, California. Their prescriptions cost Medicare Part D more than their services did: $318,984 for 1,111 claims, against $87,761 paid for services in 2024. Madrigal Pharmaceuticals was the largest of 6 companies reporting payments in 2025, $719.67 in all, mostly food and beverage. Lists Alhambra Hospital Medical Center as a hospital affiliation. A record with the same name and state is on the OIG exclusion list; it carries no NPI, so check it before acting.
Overview
| NPI | 1053343434 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M. D. |
| Sole proprietor | Yes |
| NPI issued | Jul 7, 2006 |
| Last updated in NPPES | Mar 3, 2015 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | A43296 | CA |
Exclusion screening
Possible match: verify before acting. The OIG list has a record with the same name in California, but that record carries no NPI, so it may be a different person or business.
| Matched by | Name on OIG list | Exclusion type | Excluded since | Location |
|---|---|---|---|---|
| Name + state | Dennis W. Chan | 1128b4 | Nov 20, 2005 | Sacramento, CA |
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | Possible (name) | See above |
| North Carolina Medicaid · Nov 4, 2026 | No match | — |
| New York OMIG · Nov 4, 2026 | No match | — |
| Ohio Medicaid · Nov 4, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 4, 2026 | No match | — |
| Washington HCA · Nov 4, 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 | 510 |
|---|---|
| Services billed | 925 across 14 procedure codes |
| Paid by Medicare | $87,761 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,111 · 1,287 30-day fills |
|---|---|
| Patients | 494 |
| Total drug cost | $318,984 |
| Generic share | 83% of claims |
Education and affiliations
| Graduation year | 1980 |
|---|---|
| Medicare specialty | Gastroenterology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Global Gastroenterology Group IncMonterey Park, CA · 2 clinicians
Hospital affiliation
- Alhambra Hospital Medical CenterAlhambra, CA
Industry payments (Open Payments)
- 2025$719.67 · 15 payments from 6 companies
- 2024$847.46 · 13 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Madrigal Pharmaceuticals | $227.29 | 4 |
| Ardelyx, Inc. | $149.96 | 5 |
| Pfizer Inc. | $125.00 | 1 |
| Novo Nordisk Inc | $124.95 | 1 |
| Janssen Biotech, Inc. | $56.11 | 2 |
What the 2025 payments were for
- Food and Beverage$719.67 · 15 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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