Matthew S. Chang, M.D.
NPI 1598949521ActiveIndividual· Internal Medicine, Gastroenterology· Palo Alto, CA
Internal Medicine, Gastroenterology (M.D.) in Palo Alto, California, trained at University of Michigan Medical School (class of 2006). Part D covered 616 prescriptions written in 2024, 88% of them generic. Abbvie Inc. reported $34.45 in payments in 2025, mostly food and beverage.
Overview
| NPI | 1598949521 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Dec 27, 2007 |
| Last updated in NPPES | Dec 17, 2021 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | A133674 | CA |
| Internal Medicine | 207R00000X | 250090 | MA |
| Internal Medicine | 207R00000X | 245746 | NY |
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) |
|---|
Part D prescriptions in 2024
| Prescriptions (claims) | 616 · 1,108 30-day fills |
|---|---|
| Patients | 355 |
| Total drug cost | $256,176 |
| Generic share | 88% of claims |
Education and affiliations
| Medical school | University of Michigan Medical School |
|---|---|
| Graduation year | 2006 |
| Medicare specialty | Gastroenterology |
Medical group
- Permanente Medical Group IncOakland, CA · 10,996 clinicians
Industry payments (Open Payments)
- 2025$34.45 · 1 payment from 1 company
- 2024$24.05 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $34.45 | 1 |
What the 2025 payments were for
- Food and Beverage$34.45 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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