Gwendolen Chang, M.D.
NPI 1386807402ActiveIndividual· Internal Medicine· San Leandro, CA
Internal Medicine (M.D.) in San Leandro, California, trained at Stanford University School of Medicine (class of 2007). Their prescriptions cost Medicare Part D more than their services did: $942,374 for 2,140 claims, against $295,114 paid for services in 2024. Fresenius USA Marketing, Inc. was the largest of 15 companies reporting payments in 2025, $1,616 in all, mostly food and beverage.
Overview
| NPI | 1386807402 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Jul 9, 2008 |
| Last updated in NPPES | Dec 4, 2013 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A106132 | CA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Nephrology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 488 |
|---|---|
| Services billed | 2,601 across 35 procedure codes |
| Paid by Medicare | $295,114 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,140 · 4,041 30-day fills |
|---|---|
| Patients | 243 |
| Total drug cost | $942,374 |
| Generic share | 74% of claims |
Education and affiliations
| Medical school | Stanford University School of Medicine |
|---|---|
| Graduation year | 2007 |
| Medicare specialty | Nephrology |
| Telehealth | Offers telehealth |
Medical group
- West Coast KidneyDaly City, CA · 56 clinicians
Hospital affiliations
- Alameda HospitalAlameda, CA
- Alta Bates Summit Medical CenterOakland, CA
- Eden Medical CenterCastro Valley, CA
- Highland HospitalOakland, CA
Other facilities
- Davita East Bay Peritoneal Dialysis CenterDialysis facility · San Leandro, CA
- Davita San Leandro Marina DialysisDialysis facility · San Leandro, CA
- Rai - Bancroft Ave - OaklandDialysis facility · Oakland, CA
- Shc San LeandroDialysis facility · San Leandro, CA
Industry payments (Open Payments)
- 2025$1,616 · 68 payments from 15 companies
- 2024$1,284 · 53 payments from 16 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Fresenius USA Marketing, Inc. | $466.14 | 22 |
| Novartis Pharmaceuticals Corporation | $226.28 | 8 |
| Astrazeneca Pharmaceuticals LP | $207.30 | 9 |
| Otsuka America Pharmaceutical, Inc. | $185.77 | 8 |
| Bayer Healthcare Pharmaceuticals Inc. | $89.03 | 3 |
What the 2025 payments were for
- Food and Beverage$1,564 · 65 payments
- Education$52.62 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 76 internal medicine physicians in San Leandro · All internal medicine physicians in California