Quick answers
- Where does William E. Rietkerk see patients?
- Medicare's clinician data lists 1 practice location in Thousand Oaks, CA. Call before your visit to confirm the address.
- What is William E. Rietkerk's specialty?
- Medicare lists Dermatology as the primary specialty.
- Does William E. Rietkerk accept Medicare assignment?
- Yes. Medicare's clinician data says William E. Rietkerk accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for William E. Rietkerk?
- (805) 497-7539, as listed in official Medicare / NPI Registry data.
- What is William E. Rietkerk's NPI number?
- 1720311400. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where William E. Rietkerk is enrolled with Medicare (CMS data updated 2026-10-02).
- 55 Rolling Oaks Dr, Suite 200Thousand Oaks, CA 91361 (805) 497‑7539
Group practices
Medicare enrollment lists William E. Rietkerk as a member of this group (CMS data updated 2026-10-02).
- J Robert West MD Inc138 clinicians in the group
Specialties
- Dermatologyprimary
Other dermatologists in Thousand Oaks
Clinicians with the same Medicare primary specialty in Thousand Oaks, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Irvine, California College Of Medicine |
| Graduation year | 2008 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1720311400 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians