Merrill K. Shum, M.D.
NPI 1982819702ActiveIndividual· Internal Medicine, Hematology & Oncology· Whittier, CA
Internal Medicine, Hematology & Oncology (M.D.) with Cancer and Blood Specialty Clinic, practicing in Whittier, California. In 2024 Medicare paid $2,375,662 for 461 patients, and Part D covered 576 of their prescriptions, 61% of them generic. Pfizer Inc. was the largest of 69 companies reporting payments in 2025, $6,659 in all, mostly food and beverage. Lists Pih Health Downey Hospital and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1982819702 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | May 14, 2007 |
| Last updated in NPPES | Aug 19, 2019 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | A98845 | CA |
| Internal Medicine, Hematology & Oncology | 207RH0003X | MD428611 | PA |
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 - Hematology/Oncology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 461 |
|---|---|
| Services billed | 104,204 across 103 procedure codes |
| Paid by Medicare | $2,375,662 |
Part D prescriptions in 2024
| Prescriptions (claims) | 576 · 818 30-day fills |
|---|---|
| Patients | 117 |
| Total drug cost | $1,686,703 |
| Generic share | 61% of claims |
Education and affiliations
| Graduation year | 2000 |
|---|---|
| Medicare specialty | Hematology/Oncology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Cancer and Blood Specialty ClinicLos Alamitos, CA · 18 clinicians
Hospital affiliations
- Pih Health Downey HospitalDowney, CA
- Pih Health Hospital-WhittierWhittier, CA
- Whittier Hospital Medical CenterWhittier, CA
Other facilities
- Barlow Respiratory HospitalLong-term care hospital · Los Angeles, CA
Industry payments (Open Payments)
- 2025$6,659 · 260 payments from 69 companies
- 2024$16,545 · 283 payments from 51 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Pfizer Inc. | $570.36 | 23 |
| Novartis Pharmaceuticals Corporation | $519.48 | 15 |
| Janssen Biotech, Inc. | $368.27 | 19 |
| Astrazeneca Pharmaceuticals LP | $325.39 | 14 |
| Eisai Inc. | $305.55 | 10 |
What the 2025 payments were for
- Food and Beverage$6,200 · 254 payments
- Long term medical supply or device loan$282.73 · 3 payments
- Education$175.92 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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