William Rietkerk, MD MBA
NPI 1720311400 · Dermatology Physician · Thousand Oaks, CA
Enrolled with Medicare as Practitioner - Dermatology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Rietkerk, MD MBA is a Dermatology Physician provider in Thousand Oaks, CA (NPI 1720311400).
Provider details
- NPI number
- 1720311400
- Entity type
- Individual
- Primary specialty
- Dermatology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD MBA
- Sex
- Male
- Sole proprietor
- No
- License
- A141249 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
16 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
15,294 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Destruction of Precancer Skin Growth, 2-14 Growths17003 | 5,448 | $8 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 2,775 | $97 |
| Destruction of Precancer Skin Growth, 1 Growth17000 | 1,482 | $55 |
| Pathology Examination of Tissue Using a Microscope, Intermediate Complexity88305 | 1,384 | $38 |
| Destruction of Skin Growth, 1-14 Growths17110 | 1,131 | $126 |
| Superficial And/Or Low Voltage Radiation Treatment Delivery77401 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 20 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Betamethasone Dipropionate | 197 | 152 |
| Ketoconazole | 170 | 80 |
| Ciclopirox Olaminebrand: Ciclopirox | 165 | 113 |
| Triamcinolone Acetonide | 160 | 134 |
| Mupirocin | 117 | 101 |
| Clobetasol Propionate | 84 | 43 |
| Fluorouracil | 70 | 58 |
| Metronidazole | 49 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,919 across 79 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2009-09-11
- Last updated
- 2022-07-21
Frequently asked questions
- What is William Rietkerk's NPI number?
- William Rietkerk's National Provider Identifier (NPI) is 1720311400, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Rietkerk's specialty?
- William Rietkerk is listed in the NPPES registry with a primary specialty of Dermatology Physician (Allopathic & Osteopathic Physicians).
- Where is William Rietkerk located?
- William Rietkerk's practice location on file with NPPES is 55 Rolling Oaks Dr Ste 200, Thousand Oaks, CA 91361-1010.
- What is William Rietkerk's phone number?
- The practice phone number listed in the NPPES registry for William Rietkerk is (212) 661-3376.
- Does William Rietkerk accept Medicare?
- William Rietkerk is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Rietkerk's NPI active?
- Yes — William Rietkerk's NPI (1720311400) is active in the NPPES registry as of the last update on 2022-07-21.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.