WILLIAM W CHOU (MD) – Radiation Oncology Physician, NPI 1790713253
Radiation Oncology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
677 RADIATION ONCOLOGY in CA
Provider Addresses for WILLIAM W CHOU (MD)
27800 Medical Center Rd
Suite 160
Mission Viejo, CA 926916410
Phone: (949) 364-9120
Fax: (949) 364-8465
Type: Location
149, Treehouse, Quail Hill, Irvine, Orange County, California, 92603, United States
IRVINE, CA 926030692
Phone: (949) 573-9560
Type: Mailing
Medical Center Road, Mission Viejo, Orange County, California, 92690, United States
MISSION VIEJO, CA 926916400
Phone: (949) 573-9560
Fax: (949) 364-4276
Type: Location
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 12 Open Payments records for all available years, with a total value of $807.
Total Amount is formed as General ($807) + Research ($0) + Ownership ($0) = $807.
Last reported payment date: 2024-05-21 • Largest payer in this snapshot: BeiGene USA, Inc. ($458).
Total Amount
$807
General + Research + Ownership
Payments
12
Total payment records
General Amount
$807
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2024-05-21
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| BeiGene USA, Inc. | $458 |
| Brainlab, Inc. | $152 |
| Sumitomo Pharma America, Inc. | $122 |
| Siemens Medical Solutions USA, Inc. | $48 |
| Elekta, Inc. | $27 |
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: 2006-08-07
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 |
|---|---|---|---|---|
| I20060807000283 | I | Radiation 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 |
|---|---|---|---|---|
| 77014 | Ct guidance for insertion of radiation therapy fields | 1,853 | 82 | $0 |
| 77300 | Calculation of radiation therapy dose | 482 | 95 | $0 |
| 77427 | Radiation treatment management, 5 treatment sessions | 454 | 99 | $0 |
| 77334 | Design and construction of complex radiation treatment device | 272 | 99 | $0 |
| 99213 | Established patient office or other outpatient visit, 20-29 minutes | 160 | 104 | $0 |
Insurance plans in this area (ZIP 92691)
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Provider's Procedures
Group practice members
| Name | Specialty | State |
|---|---|---|
| - | CA | |
| Radiation Oncology | IL |
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