Timothy Euiwon Byun, MD
NPI 1871545012ActiveIndividual· Internal Medicine, Hematology & Oncology· Orange, CA
Internal Medicine, Hematology & Oncology (MD) in Orange, California, trained at Rush Medical College of Rush University (class of 1998). Their prescriptions cost Medicare Part D more than their services did: $6,002,440 for 1,599 claims, against $509,476 paid for services in 2024. Astrazeneca Pharmaceuticals LP was the largest of 50 companies reporting payments in 2025, $5,583 in all, mostly food and beverage.
Overview
| NPI | 1871545012 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | May 16, 2006 |
| Last updated in NPPES | Jun 4, 2024 |
| Certified by provider | Jun 4, 2024 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | A70195 | 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 | 364 |
|---|---|
| Services billed | 16,511 across 71 procedure codes |
| Paid by Medicare | $509,476 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,599 · 2,455 30-day fills |
|---|---|
| Patients | 282 |
| Total drug cost | $6,002,440 |
| Generic share | 69% of claims |
Education and affiliations
| Medical school | Rush Medical College of Rush University |
|---|---|
| Graduation year | 1998 |
| Medicare specialty | Hematology/Oncology |
| Telehealth | Offers telehealth |
Medical group
- Providence Medical FoundationVictorville, CA · 1,466 clinicians
Hospital affiliation
- Providence St. Joseph HospitalOrange, CA
Other facilities
- Providence at Home With Compassus Home Health Orange CountyHome health agency · Anaheim, CA
Industry payments (Open Payments)
- 2025$5,583 · 277 payments from 50 companies
- 2024$6,726 · 235 payments from 45 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astrazeneca Pharmaceuticals LP | $713.10 | 29 |
| Celgene Corporation | $387.08 | 29 |
| Pfizer Inc. | $358.97 | 19 |
| E.R. Squibb & Sons, L.L.C. | $289.84 | 23 |
| Abbvie Inc. | $247.12 | 14 |
What the 2025 payments were for
- Food and Beverage$5,560 · 276 payments
- Education$23.10 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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