John Charles Michalak, M.D.
Hematology & Oncology Physician · Sioux City, IA
John Charles Michalak, M.D. is a hematology & oncology physician with a practice address in Sioux City, Iowa, and NPI 1497727663, issued on Feb 2, 2006. Check the license (Iowa 21969, as entered in NPPES) on the Iowa Board of Medicine; the Medicare figures below come from public CMS files.
- Name
- John Charles Michalak
- Credential
- M.D.
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- 21969 IA
Self-reported in NPPES; status is on the state search - Practice location
- 230 Nebraska St, Sioux City, IA 51101
- Phone
- (712) 252-0088
- Enumerated
- Feb 2, 2006
- Record last updated
- Jul 13, 2026
- Fax
- (712) 252-5271
- Medicaid ID
- 0171322 IA
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 90 in Iowa → Look up another NPI →
Also registered at 230 Nebraska St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- August Anderson, MDRadiation Oncology Physician1093342859
- Shari Black, CNPAdult Health Nurse Practitioner1831152925
- Chandana Javvaji, M.D.Hematology & Oncology Physician1821437716
- Cynthia Jurado Marquez, ARNPFamily Nurse Practitioner1972337608
- Stephen Kahanic, MDHematology & Oncology Physician1962474155
- Muaiad Kittaneh, M.D.Medical Oncology Physician1730350794
Verify John Charles Michalak in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIowa Board of Medicine
Search for license 21969Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% fewer Medicare Part D claims than the average hematology & oncology physician in 2024
13 Medicare Part D claims, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D.
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.
Industry payments in 2024: $24.59
1 payment: food and beverage; the largest payer was Pfizer Inc. The 8,560 providers of this specialty with any payment received $7,481.41 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.
John Charles Michalak among 90 hematology & oncology physician records in Iowa
John Charles Michalak, M.D. is one of 90 hematology & oncology physician records with a practice address in Iowa. 74% 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 19% of them.
- NPI issued2006 · 19% of these records are older, 46% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileNo · 61% of these records are
- Record last updated2026 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a Iowa practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in Iowa
There are 90 hematology & oncology physician records in Iowa.
All 90 in Iowa → Every provider in Sioux City → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Chandana Javvaji, M.D.Sioux City, IA 511011821437716
- Stephen Kahanic, MDSioux City, IA 511011962474155
- Radha Rao, M.D.Sioux City, IA 511011699746016
- Donald Wender, M.D.Sioux City, IA 511011861463275
- Glenn Preston, M.D.Spencer, IA 513011194796243
- Mukund Nadipuram, MDWaterloo, IA 507021962444349
- Hussain Naseri, M.D.Waterloo, IA 507021154646149
- Jasjeet Sangha, MDWaterloo, IA 507011215980602
Common questions
What is John Charles Michalak, M.D.'s NPI number?
John Charles Michalak, M.D.'s National Provider Identifier (NPI) is 1497727663, issued on Feb 2, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John Charles Michalak, M.D. located?
The NPPES record lists a practice address at 230 Nebraska St, Sioux City, IA, 51101. Phone: (712) 252-0088. Providers update this record themselves, so call before visiting.
How can I verify John Charles Michalak, M.D.'s license?
NPPES lists Iowa license number 21969, as entered by the provider. Search the Iowa Board of Medicine at https://dial.iowa.gov/about-dial/boards-and-commissions/medicine. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John Charles Michalak, M.D. prescribe under Medicare Part D?
In 2024, John Charles Michalak, M.D. had 13 Medicare Part D claims; the average among hematology & oncology physician prescribers was 877. 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.