Dr. John Charles Michalak, MD
- Part D claims, 2024
- 13
- Industry payments
- $25
- Affiliated sites
- 1
- Medical group
- 1
- State license
- 1
- Practice address
- 230 Nebraska St, Sioux City, IA 51101-1733
- Practice phone
- Call (712) 252-0088
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Siouxland Hematology Oncology Associates
Medical specialty practice · Sioux City, Iowa
Find Dr. Michalak's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. John Charles Michalak is a hematologist and oncologist in Sioux City, Iowa
Dr. Michalak practices at Siouxland Hematology Oncology Associates in Sioux City, Iowa.
Dr. Michalak's NPI, 1497727663, was assigned on February 2, 2006. Dr. Michalak holds Iowa license 21969.
- NPI
- 1497727663NPI Registry (opens in a new tab)
- NPI enumeration date
- February 2, 2006
- NPI status
- Active
- Practice phone
- (712) 252-0088
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John Charles Michalak practices at Siouxland Hematology Oncology Associates in Sioux City, Iowa
Dr. Michalak's primary practice is Siouxland Hematology Oncology Associates, at 230 Nebraska St, Sioux City, IA 51101-1733. The practice phone is (712) 252-0088.
- Siouxland Hematology Oncology Associates230 Nebraska St, Sioux City, IA 51101-1733Phone(712) 252-0088
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John Charles Michalak is affiliated with 1 site of care and 1 medical group
Dr. Michalak's primary practice is Siouxland Hematology Oncology Associates in Sioux City, Iowa. Dmand AI also links Dr. Michalak to 1 medical group, named with a free account.
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dmand AI tracks the EHR system at Dr. John Charles Michalak's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Michalak practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Siouxland Hematology Oncology Associates | Available with a free account |
| +1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. John Charles Michalak is one of 77 hematologists and oncologists in Iowa
Hematology and oncology is Dr. Michalak's primary specialty in the NPI Registry, under taxonomy code 207RH0003X. Dr. Michalak is licensed in Iowa.
Specialties and state licenses
- Hematology and oncology, IowaPrimary
Hematologists and oncologists near Dr. Michalak
Counts of hematologists and oncologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. John Charles Michalak's patients have a median age of 40
Across all payers, Dmand AI patient panel data puts Dr. Michalak's median patient age at 40, with 25% women.
Dr. Michalak's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 40
Patient panel by sex, all payers
- Women25%
- Men75%
Source: Dmand AI Patient Panel Data
Dr. John Charles Michalak wrote 13 Medicare Part D claims in 2024
In 2024, Dr. Michalak wrote 13 Medicare Part D claims. 85% of them were for generic drugs. CMS names the drug for 12 of them, across 1 drug with 11 or more claims each, at $166 in total drug cost. In 2016, CMS named 20 claims across 1 drug.
Dr. Michalak's Part D claims by kind of drug, 2024
- Generic11 claims85%
- Brand-name and other2 claims15%
Dr. Michalak's most prescribed drugs by claims, 2021
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Part D claims for drugs CMS names, 2016 to 2021
- 2016
- 2021
- Claims for drugs CMS names
- 2016: 202021: 1240%
Drugs named by CMS: 1 in 2021, 1 in 2016.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Dr. John Charles Michalak received $25 in industry payments in 2024
CMS Open Payments shows 1 general payment to Dr. Michalak from 1 drug or device company in 2024. Food and beverage make up the largest share, 100% of the total. Pfizer Inc. paid the most, $25.
Companies that paid Dr. Michalak the most, 2024 to 2024
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. John Charles Michalak's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. John Charles Michalak
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. John Charles Michalak's NPI number?
Dr. John Charles Michalak's NPI number is 1497727663. It was assigned on February 2, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. John Charles Michalak?
Dr. John Charles Michalak is a hematologist and oncologist in Sioux City, Iowa. The primary specialty in the NPI Registry is Hematology & Oncology Physician (taxonomy code 207RH0003X).
Where does Dr. John Charles Michalak practice?
Dr. Michalak practices at 230 Nebraska St, Sioux City, IA 51101-1733. Dr. Michalak's primary practice is Siouxland Hematology Oncology Associates in Sioux City, Iowa. Dmand AI also links Dr. Michalak to 1 medical group.
What is Dr. John Charles Michalak's office phone number?
The practice phone on file for Dr. Michalak is (712) 252-0088.
What is Dr. John Charles Michalak's medical license number?
Dr. Michalak holds Iowa license 21969.
What drugs does Dr. John Charles Michalak prescribe most?
In 2021 Medicare Part D data, Dr. Michalak's most prescribed drugs by claims were Pantoprazole Sodium.
Has Dr. John Charles Michalak received payments from drug or device companies?
CMS Open Payments shows $25 in general payments to Dr. Michalak from 1 company from 2024 to 2024. The largest total came from Pfizer Inc.
How long has Dr. John Charles Michalak been practicing?
Dr. Michalak's NPI was assigned in 2006.
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