Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

John Charles Michalak, MD

Individual provider Hematology & Oncology Physician · NPI 1497727663

John Charles Michalak, MD is a Hematology & Oncology Physician in Sioux City, Iowa. Licensed in Iowa. Registered with an NPI since 2006.

Licensed in
IA
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

230 Nebraska St
Sioux City, IA 51101-1733
Phone: (712) 252-0088
Fax: (712) 252-5271
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Hematology & Oncology Physician (primary) Taxonomy 207RH0003X · Licence 21969 (IA)

Record details

NPI number1497727663
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedFebruary 2, 2006
Last updated in NPPESJuly 13, 2026

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