Willis John Rieker, M.D.
Cytopathology Physician · Beloit, WI
Willis John Rieker, M.D. is a cytopathology physician with a practice address in Beloit, Wisconsin, and NPI 1689714834, issued on Feb 7, 2007. Check the license (Wisconsin 35629-020, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Willis John Rieker
- Credential
- M.D.
- Primary taxonomy
- Cytopathology Physician 207ZC0500X
- License number
- 35629-020 WI
Self-reported in NPPES; status is on the state search - Practice location
- 1969 W Hart RD, Beloit, WI 53511
- Phone
- (608) 364-5131
- Enumerated
- Feb 7, 2007
- Record last updated
- Sep 11, 2025
- Fax
- (608) 364-3185
- Medicaid ID
- 32846400 WI
- Medicare enrollment
- Enrolled (PECOS I20111227000167); accepts Medicare assignment
- Medical or professional school
- Loyola University Of Chicago, Stritch School Of Medicine, 1984
- Entity
- Type 1 · individual
8 nearest cytopathology physician records → All 10 in Wisconsin → Look up another NPI →
Also registered at 1969 W Hart RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Maria Maria Anleu-Smith, M.D.Child & Adolescent Psychiatry Physician1447367248
- Ryan Arthur, MDEmergency Medicine Physician1316444771
- Emily Berquist, APNPFamily Nurse Practitioner1972487817
- Bradley Billeter, CNPNurse Practitioner1427902212
Verify Willis John Rieker in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 35629-020Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
92% fewer Medicare Part D claims than the average cytopathology physician in 2024
17 Medicare Part D claims, against an average of 211 among the 12 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of 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.
Bills Medicare through one group practice
- Hart Road Pathology, SCBeloit, WI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Willis John Rieker among 10 cytopathology physician records in Wisconsin
Willis John Rieker, M.D. is one of 10 cytopathology physician records with a practice address in Wisconsin. 70% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 70% of them.
- NPI issued2007 · 70% of these records are older, 10% newer
- In a Medicare fileYes · 70% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Record last updated2025 · 50% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207ZC0500X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Cytopathology Physician providers in Wisconsin
There are 10 cytopathology physician records in Wisconsin.
All 10 in Wisconsin → Every provider in Beloit → Cytopathology Physician nationwide →
The 8 cytopathology physician records with the nearest ZIP codes
- Daniel Iyama-Kurtycz, MDMadison, WI 537921184686362
- Kelly Olson, MDMadison, WI 537921265926604
- Suzanne Selvaggi, MDMadison, WI 537921710948237
- Jimmie Stewart, MDMadison, WI 537921467414649
- Richard Vander Heide, MD, PH.D.Marshfield, WI 544491639116148
- Sabine Hale, MDStevens Point, WI 544811982737904
- Mark Hofer, MDEau Claire, WI 547011134177538
- Scott Martin, MDEau Claire, WI 547031073590956
Common questions
What is Willis John Rieker, M.D.'s NPI number?
Willis John Rieker, M.D.'s National Provider Identifier (NPI) is 1689714834, issued on Feb 7, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Willis John Rieker, M.D. located?
The NPPES record lists a practice address at 1969 W Hart RD, Beloit, WI, 53511. Phone: (608) 364-5131. Providers update this record themselves, so call before visiting.
How can I verify Willis John Rieker, M.D.'s license?
NPPES lists Wisconsin license number 35629-020, as entered by the provider. Search the Wisconsin Medical Examining Board at https://dsps.wi.gov/Pages/BoardsCouncils/MEB/Default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Willis John Rieker, M.D. prescribe under Medicare Part D?
In 2024, Willis John Rieker, M.D. had 17 Medicare Part D claims; the average among cytopathology physician prescribers was 211. Part D covers Medicare prescriptions only.
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.