William Edward Rietkerk, MD MBA
NPI 1720311400ActiveIndividual· Dermatology· Thousand Oaks, CA
Dermatology (MD MBA) in Thousand Oaks, California, trained at University of California, Irvine, California College of Medicine (class of 2008). 1,681 Medicare patients in 2024, $704,474 paid; nearly all of their 1,541 Part D prescriptions were generic (98%). Ucb, Inc. was the largest of 20 companies reporting payments in 2025, $3,828 in all, mostly consulting fees.
Overview
| NPI | 1720311400 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD MBA |
| Sole proprietor | No |
| NPI issued | Sep 11, 2009 |
| Last updated in NPPES | Jul 21, 2022 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Dermatology Primary | 207N00000X | A141249 | CA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Dermatology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 1,681 |
|---|---|
| Services billed | 15,771 across 58 procedure codes |
| Paid by Medicare | $704,474 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,541 · 1,817 30-day fills |
|---|---|
| Patients | 663 |
| Total drug cost | $98,379 |
| Generic share | 98% of claims |
Education and affiliations
| Medical school | University of California, Irvine, California College of Medicine |
|---|---|
| Graduation year | 2008 |
| Medicare specialty | Dermatology |
Medical group
- J Robert West MD IncLas Vegas, NV · 138 clinicians
Industry payments (Open Payments)
- 2025$3,828 · 68 payments from 20 companies
- 2024$1,919 · 79 payments from 17 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Ucb, Inc. | $2,125 | 5 |
| Regeneron Healthcare Solutions, Inc. | $372.56 | 9 |
| Sun Pharmaceutical Industries Inc. | $250.68 | 9 |
| Janssen Biotech, Inc. | $184.76 | 6 |
| Leo Pharma Inc. | $150.58 | 9 |
What the 2025 payments were for
- Consulting Fee$1,950 · 1 payment
- Food and Beverage$1,694 · 65 payments
- Education$184.65 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 23 dermatologists in Thousand Oaks · All dermatologists in California