John Gerard Onderak, D.D.S.
General Practice Dentistry · Beloit, WI
John Gerard Onderak, D.D.S. is a general practice dentistry with a practice address in Beloit, Wisconsin, and NPI 1528176492, issued on Aug 29, 2006. Check the license (Wisconsin 3261, as entered in NPPES) with the Wisconsin board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- John Gerard Onderak
- Credential
- D.D.S.
- Primary taxonomy
- General Practice Dentistry 1223G0001X
- License number
- 3261 WI
Self-reported in NPPES; status is on the state search - Practice location
- 1215 Cranston RD, Beloit, WI 53511
- Phone
- (608) 363-9400
- Enumerated
- Aug 29, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (608) 363-9837
- Entity
- Type 1 · individual
8 nearest general practice dentistry records → All 2,305 in Wisconsin → Look up another NPI →
Verify John Gerard Onderak in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Wisconsin board licenses this profession
Search for license 3261Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
87% more Medicare Part D claims than the average general practice dentistry in 2024
155 Medicare Part D claims for 87 beneficiaries, against an average of 83 among the 70,290 providers of this specialty who prescribed in Part D.
Most prescribed
- Amoxicillin127 claims
- Clindamycin Hcl14 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.
John Gerard Onderak among 2,305 general practice dentistry records in Wisconsin
John Gerard Onderak, D.D.S. is one of 2,305 general practice dentistry records with a practice address in Wisconsin. 57% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 3% of them.
- NPI issued2006 · 3% of these records are older, 67% newer
- In a Medicare fileYes · 57% of these records are
- In the CMS Doctors and Clinicians fileNo · under 1% of these records are
- Record last updated2007 · 75% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 1223G0001X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
11 general practice dentistry records list a practice address in Beloit
They are 11 of the 706 NPPES records with a practice address in Beloit, and 2,305 general practice dentistry records in Wisconsin.
All 2,305 in Wisconsin → Every provider in Beloit → General Practice Dentistry nationwide →
The 8 general practice dentistry records with the nearest ZIP codes
- Timothy Chapman, D.D.S.Beloit, WI 535111417120379
- Edward Chiera, DDSBeloit, WI 535111821180464
- Prachi Desai, DMDBeloit, WI 535111700625340
- Ronald Duffy, DDSBeloit, WI 535111558560318
- Robert Grigsby, DDSBeloit, WI 535111912915661
- Dennis Nosek, DDSBeloit, WI 535111326249152
- Mihaela Popa, D.M.D.Beloit, WI 535111013101047
- Cynthia Riffle, DDSBeloit, WI 535111831236587
Common questions
What is John Gerard Onderak, D.D.S.'s NPI number?
John Gerard Onderak, D.D.S.'s National Provider Identifier (NPI) is 1528176492, issued on Aug 29, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John Gerard Onderak, D.D.S. located?
The NPPES record lists a practice address at 1215 Cranston RD, Beloit, WI, 53511. Phone: (608) 363-9400. Providers update this record themselves, so call before visiting.
How can I verify John Gerard Onderak, D.D.S.'s license?
NPPES lists Wisconsin license number 3261, as entered by the provider. Search the Wisconsin board that licenses this profession; the NPPES record confirms identity only.
How much does John Gerard Onderak, D.D.S. prescribe under Medicare Part D?
In 2024, John Gerard Onderak, D.D.S. had 155 Medicare Part D claims for 87 beneficiaries; the average among general practice dentistry prescribers was 83. 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.