TIMOTHY EUIWON BYUN (MD) – Hematology & Oncology Physician, NPI 1871545012
Hematology & Oncology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
1,531 HEMATOLOGY/ONCOLOGY in CA
Provider Addresses for TIMOTHY EUIWON BYUN (MD)
1010 W La Veta Ave
#200
Orange, CA 928684300
Phone: (714) 835-1800
Fax: (714) 835-1811
Type: Location
1010, West La Veta Avenue, Orange, Orange County, California, 92868, United States
#200
ORANGE, CA 928684300
Phone: (714) 835-1800
Fax: (714) 835-1811
Type: Mailing
805 W LA VETA AVE STE 101
ORANGE, CA 928683928
Phone: (714) 835-1800
Fax: (714) 835-1811
Type: Mailing
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 449 Open Payments records for all available years, with a total value of $21,777.
Total Amount is formed as General ($21,777) + Research ($0) + Ownership ($0) = $21,777.
Last reported payment date: 2024-12-19 • Largest payer in this snapshot: AstraZeneca Pharmaceuticals LP ($7,579).
Total Amount
$21,777
General + Research + Ownership
Payments
449
Total payment records
General Amount
$21,777
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2024-12-19
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| AstraZeneca Pharmaceuticals LP | $7,579 |
| Exelixis Inc. | $3,200 |
| E.R. Squibb & Sons, L.L.C. | $1,920 |
| Novartis Pharmaceuticals Corporation | $1,168 |
| Janssen Scientific Affairs, LLC | $1,090 |
Medicare Enrollment & Revalidation
Source: CMS public data · Not endorsed by CMS ·
Educational use only—not medical, billing, or legal advice.
PECOS enrollment status
Participating (accepts Medicare assignment)
Enrollment effective: 2004-07-13
PECOS data refreshed: 2026-05-27
Medicare revalidation (CMS due date list)
Due date not assigned yet
CMS is tracking this Medicare enrollment for revalidation, but has not published a due date.
Enrollment records
1
Earliest due date
Not assigned (TBD)
CMS data updated
2026-06-01
Revalidation progress
- Medicare enrolled
- On CMS revalidation list
- Due date assigned
- Revalidate in PECOS
CMS enrollment records
| Enrollment ID | Type | Specialty | State | Due date |
|---|---|---|---|---|
| I20040713001680 | I | Hematology/Oncology | CA | TBD |
What to do next
- No action required while the due date shows TBD.
- Check the CMS Revalidation Lookup Tool periodically — CMS updates the list about every 60 days.
- Do not submit a revalidation application in PECOS until CMS publishes a concrete due date.
Prepare CMS-855 application → · Look up this NPI in PECOS → · Verify on CMS PECOS
Medicare Utilization (FFS)
Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·
Educational use only—not medical, billing, or legal advice.
Top Medicare procedures (2023) · refreshed 2026-05-27
| HCPCS | Description | Services | Beneficiaries | Medicare allowed |
|---|---|---|---|---|
| 99214 | Established patient office or other outpatient visit, 30-39 minutes | 546 | 280 | $0 |
| 85025 | Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count | 261 | 91 | $0 |
| 36415 | Insertion of needle into vein for collection of blood sample | 257 | 96 | $0 |
| 99233 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 101 | 23 | $0 |
| 80053 | Blood test, comprehensive group of blood chemicals | 74 | 34 | $0 |
Insurance plans in this area (ZIP 92868)
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Group practice members
| Name | Specialty | State |
|---|---|---|
| Nurse Practitioner | CA | |
| - | CA | |
| - | CA | |
| - | WA | |
| - | ME | |
| - | CA | |
| - | CA | |
| - | CA | |
| - | CA | |
| - | CA |
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