Marcus Wesley Lum, MD
NPI 1003839242ActiveIndividual· Family Medicine· La Mirada, CA
Family Medicine (MD) with Imperial Primary Care Medical Group, practicing in La Mirada, California. Their prescriptions cost Medicare Part D more than their services did: $632,818 for 7,643 claims, against $30,634 paid for services in 2024. Astellas Pharma US Inc was the largest of 16 companies reporting payments in 2025, $953.84 in all, mostly food and beverage. Lists Pih Health Hospital-Whittier as a hospital affiliation.
Overview
| NPI | 1003839242 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jul 26, 2006 |
| Last updated in NPPES | Jul 8, 2007 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Family Medicine Primary | 207Q00000X | G073347 | 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 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 - Family Practice (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 126 |
|---|---|
| Services billed | 469 across 41 procedure codes |
| Paid by Medicare | $30,634 |
Part D prescriptions in 2024
| Prescriptions (claims) | 7,643 · 18,530 30-day fills |
|---|---|
| Patients | 565 |
| Total drug cost | $632,818 |
| Generic share | 87% of claims |
Education and affiliations
| Graduation year | 1990 |
|---|---|
| Medicare specialty | Family Practice |
| Telehealth | Offers telehealth |
Medical group
- Imperial Primary Care Medical GroupLa Mirada, CA · 4 clinicians
Hospital affiliation
- Pih Health Hospital-WhittierWhittier, CA
Industry payments (Open Payments)
- 2025$953.84 · 39 payments from 16 companies
- 2024$1,012 · 49 payments from 13 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astellas Pharma US Inc | $152.81 | 4 |
| Sumitomo Pharma America, Inc. | $122.49 | 4 |
| Lilly USA, LLC | $116.95 | 6 |
| Glaxosmithkline, LLC. | $98.55 | 5 |
| Exact Sciences Corporation | $82.26 | 3 |
What the 2025 payments were for
- Food and Beverage$871.85 · 38 payments
- Education$81.99 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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