Walter Tsang, MD
NPI 1285861799ActiveIndividual· Internal Medicine, Hematology & Oncology· Highland, CA
Internal Medicine, Hematology & Oncology (MD) in Highland, California, trained at University of California, Irvine, California College of Medicine (class of 2007). Their prescriptions cost Medicare Part D more than their services did: $7,669,248 for 1,826 claims, against $125,514 paid for services in 2024. Astellas Pharma US Inc was the largest of 35 companies reporting payments in 2025, $4,786 in all, mostly food and beverage.
Overview
| NPI | 1285861799 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jun 11, 2009 |
| Last updated in NPPES | Jan 22, 2014 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | A106910 | CA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| 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 - Hematology/Oncology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 83 |
|---|---|
| Services billed | 6,811 across 36 procedure codes |
| Paid by Medicare | $125,514 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,826 · 2,982 30-day fills |
|---|---|
| Patients | 371 |
| Total drug cost | $7,669,248 |
| Generic share | 62% of claims |
Education and affiliations
| Medical school | University of California, Irvine, California College of Medicine |
|---|---|
| Graduation year | 2007 |
| Medicare specialty | Hematology/Oncology |
| Telehealth | Offers telehealth |
Medical group
- Austin J Ma MD A Professional CorporationOxnard, CA · 11 clinicians
Hospital affiliation
- Redlands Community HospitalRedlands, CA
Other facilities
- Revive Hospice Care Group, Inc.Hospice · Glendale, CA
Industry payments (Open Payments)
- 2025$4,786 · 204 payments from 35 companies
- 2024$4,124 · 177 payments from 36 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astellas Pharma US Inc | $543.85 | 16 |
| Pfizer Inc. | $408.67 | 19 |
| Novartis Pharmaceuticals Corporation | $369.38 | 22 |
| Bayer Healthcare Pharmaceuticals Inc. | $349.25 | 18 |
| Astrazeneca Pharmaceuticals LP | $251.37 | 12 |
What the 2025 payments were for
- Food and Beverage$4,087 · 196 payments
- Education$698.72 · 8 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records