William Jacob Dieter
Radiation Oncology Physician · Chicago, IL
William Jacob Dieter is a radiation oncology physician with a practice address in Chicago, Illinois, and NPI 1891572533, issued on Sep 14, 2023. Check the license (Illinois 125086179, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- William Jacob Dieter
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License numbers
- 125086179 IL
125.086179 IL
Self-reported in NPPES; status is on the state search - Practice location
- 1520 W Harrison St, Chicago, IL 60607
- Phone
- (312) 942-0712
- Enumerated
- Sep 14, 2023
- Record last updated
- Aug 5, 2025
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 277 in Illinois → Look up another NPI →
Also registered at 1520 W Harrison St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify William Jacob Dieter in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIllinois Department of Financial and Professional Regulation
Search for license 125086179Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
69% fewer Medicare Part D claims than the average radiation oncology physician in 2024
41 Medicare Part D claims for 27 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D. 15 claims were for opioids.
Most prescribed
- Oxycodone Hcl12 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.
William Jacob Dieter among 277 radiation oncology physician records in Illinois
William Jacob Dieter is one of 277 radiation oncology physician records with a practice address in Illinois. 78% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2023, is newer than 95% of them.
- NPI issued2023 · 95% of these records are older, 3% newer
- In a Medicare fileYes · 78% of these records are
- In the CMS Doctors and Clinicians fileNo · 66% of these records are
- Record last updated2025 · 49% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in Illinois
There are 277 radiation oncology physician records in Illinois.
All 277 in Illinois → Every provider in Chicago → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Nikhil Joshi, M.D.Chicago, IL 606071851722250
- Virginia ScharfChicago, IL 606071104447663
- Mohamed Abazeed, MD, PHDChicago, IL 606111205096609
- Adam Dickler, M.D.Chicago, IL 606111053387274
- Arnold Herskovic, MDChicago, IL 606111538185095
- Stanley Hoover, M.D.Chicago, IL 606111710952569
- John Kalapurakal, M.D.Chicago, IL 606111780659748
- Maryanne Marymont, M.D.Chicago, IL 606111447226105
Common questions
What is William Jacob Dieter's NPI number?
William Jacob Dieter's National Provider Identifier (NPI) is 1891572533, issued on Sep 14, 2023. An NPI identifies a provider in billing; it is not a license.
Where is William Jacob Dieter located?
The NPPES record lists a practice address at 1520 W Harrison St, Chicago, IL, 60607. Phone: (312) 942-0712. Providers update this record themselves, so call before visiting.
How can I verify William Jacob Dieter's license?
NPPES lists Illinois license number 125086179, as entered by the provider. Search the Illinois Department of Financial and Professional Regulation at https://idfpr.illinois.gov/checklicense.html. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Jacob Dieter prescribe under Medicare Part D?
In 2024, William Jacob Dieter had 41 Medicare Part D claims for 27 beneficiaries; the average among radiation oncology physician prescribers was 134. 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.