William Chunghun Sim, MD
NPI 1437256906ActiveIndividual· Internal Medicine· Downey, CA
Internal Medicine (MD) in Downey, California, trained at Stanford University School of Medicine (class of 1990). Their prescriptions cost Medicare Part D more than their services did: $3,622,029 for 38,470 claims, against $375,687 paid for services in 2024. Abbvie Inc. was the largest of 26 companies reporting payments in 2025, $1,982 in all, mostly food and beverage.
Overview
| NPI | 1437256906 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Sep 19, 2006 |
| Last updated in NPPES | Dec 20, 2011 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | G72353 | 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 - Internal Medicine (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 787 |
|---|---|
| Services billed | 5,946 across 35 procedure codes |
| Paid by Medicare | $375,687 |
Part D prescriptions in 2024
| Prescriptions (claims) | 38,470 · 57,421 30-day fills |
|---|---|
| Patients | 1,252 |
| Total drug cost | $3,622,029 |
| Generic share | 86% of claims |
Education and affiliations
| Medical school | Stanford University School of Medicine |
|---|---|
| Graduation year | 1990 |
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Frischer Medical Group IncDowney, CA · 4 clinicians
Hospital affiliations
- Memorialcare Long Beach Medical CenterLong Beach, CA
- Pih Health Downey HospitalDowney, CA
- Pih Health Hospital-WhittierWhittier, CA
Other facilities
- Ace Home Health, Inc.Home health agency · Los Angeles, CA
- Cross Care, IncHome health agency · Los Angeles, CA
- Fast Recovery Home Health Care, IncHome health agency · Buena Park, CA
- Good People Home Health, Inc.Home health agency · Fullerton, CA
- Maxlife Home Care Services, IncHome health agency · Glendale, CA
- Artemis Hospice and Palliative CareHospice · Los Angeles, CA
- Eminent Hospice Care, IncHospice · N Hollywood, CA
- SouthlandNursing home · Norwalk, CA
Industry payments (Open Payments)
- 2025$1,982 · 94 payments from 26 companies
- 2024$1,889 · 88 payments from 25 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $478.66 | 21 |
| Astrazeneca Pharmaceuticals LP | $164.09 | 8 |
| Novo Nordisk Inc | $161.38 | 9 |
| Lilly USA, LLC | $158.32 | 7 |
| Glaxosmithkline, LLC. | $155.80 | 9 |
What the 2025 payments were for
- Food and Beverage$1,982 · 94 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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