William Edward Rietkerk, MD MBA
Dermatology Physician · Thousand Oaks, CA
William Edward Rietkerk, MD MBA is a dermatology physician with a practice address in Thousand Oaks, California, and NPI 1720311400, issued on Sep 11, 2009. Check the license (California A141249, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William Edward Rietkerk
- Credential
- MD MBA
- Primary taxonomy
- Dermatology Physician 207N00000X
- License number
- A141249 CA
Self-reported in NPPES; status is on the state search - Practice location
- 55 Rolling Oaks Dr Ste 200, Thousand Oaks, CA 91361
- Phone
- (212) 661-3376
- Enumerated
- Sep 11, 2009
- Record last updated
- Jul 21, 2022
- Fax
- (212) 661-3366
- Medicare enrollment
- Enrolled (PECOS I20160819001642); accepts Medicare assignment
- Medical or professional school
- University Of California, Irvine, California College Of Medicine, 2008
- Entity
- Type 1 · individual
8 nearest dermatology physician records → All 2,083 in California → Look up another NPI →
Also registered at 55 Rolling Oaks Dr Ste 200
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Michael Bodnar, MDDermatology Physician1740296698
- Ralph Kamell, MDDermatology Physician1881609741
- Jeanette Mitchell, MDDermatology Physician1154567410
Verify William Edward Rietkerk in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A141249Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
93% more Medicare Part D claims than the average dermatology physician in 2024
1,541 Medicare Part D claims for 663 beneficiaries, against an average of 797 among the 12,802 providers of this specialty who prescribed in Part D. Brand-name drugs were 2% of claims.
Most prescribed
- Betamethasone Dipropionate197 claims
- Ketoconazole170 claims
- Ciclopirox165 claims
- Triamcinolone Acetonide160 claims
- Mupirocin117 claims
- Clobetasol Propionate84 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 77.9 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,919.27
79 payments; by number, the most common kind was food and beverage; the largest payer was Genzyme Corporation. The 10,250 providers of this specialty with any payment received $8,544.61 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- J Robert West MD IncThousand Oaks, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Edward Rietkerk among 2,083 dermatology physician records in California
William Edward Rietkerk, MD MBA is one of 2,083 dermatology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2009, is newer than 61% of them.
- NPI issued2009 · 61% of these records are older, 36% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated2008 · median 2006 among the 1,450 with a school on file
- Record last updated2022 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207N00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Dermatology Physician providers in California
There are 2,083 dermatology physician records in California.
All 2,083 in California → Every provider in Thousand Oaks → Dermatology Physician nationwide →
The 8 dermatology physician records with the nearest ZIP codes
- Michael Bodnar, MDThousand Oaks, CA 913611740296698
- Judith Feldman, MDWestlake Village, CA 913611245295575
- Karin Harp, MDWestlake Village, CA 913611518923374
- Ralph Kamell, MDThousand Oaks, CA 913611881609741
- Elissa Linstone, MDWestlake Vlg, CA 913611093761496
- Jeanette Mitchell, MDThousand Oaks, CA 913611154567410
- Anita Pakula, MDWestlake Village, CA 913611205869625
- Daphne Panagotacos, MDWestlake Village, CA 913611811091069
Common questions
What is William Edward Rietkerk, MD MBA's NPI number?
William Edward Rietkerk, MD MBA's National Provider Identifier (NPI) is 1720311400, issued on Sep 11, 2009. An NPI identifies a provider in billing; it is not a license.
Where is William Edward Rietkerk, MD MBA located?
The NPPES record lists a practice address at 55 Rolling Oaks Dr Ste 200, Thousand Oaks, CA, 91361. Phone: (212) 661-3376. Providers update this record themselves, so call before visiting.
How can I verify William Edward Rietkerk, MD MBA's license?
NPPES lists California license number A141249, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Edward Rietkerk, MD MBA prescribe under Medicare Part D?
In 2024, William Edward Rietkerk, MD MBA had 1,541 Medicare Part D claims for 663 beneficiaries; the average among dermatology physician prescribers was 797. Part D covers Medicare prescriptions only.
What is William Edward Rietkerk, MD MBA's MIPS final score?
The 2023 MIPS final score is 77.9 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.