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

Mark Ratain

Individual provider Medical Oncology Physician · NPI 1255494779

Mark Ratain is a Medical Oncology in Chicago, Illinois. Graduated from Yale University School of Medicine in 1980, 46 years ago. Practices with The University of Chicago Medical Center, a 909-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Illinois.

Years since qualifying
46
Trained at
Yale University School of Medicine
Licensed in
IL
In the registry since
2006
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Practice location Address checks out

5841 S Maryland Ave
Chicago, IL 60637-1443
Phone: (888) 824-0200
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Medical Oncology Physician (primary) Taxonomy 207RX0202X · Licence 036066554 (IL)

Record details

NPI number1255494779
Entity typeIndividual (Type 1)
GenderMale
Sole proprietorNo
NPI enumeratedDecember 18, 2006
Last updated in NPPESJune 9, 2026
Certification dateJune 9, 2026
Mailing address150 Harvester Dr, Suite 300, Burr Ridge, IL 60527-5919

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyMEDICAL ONCOLOGY
Medical schoolYALE UNIVERSITY SCHOOL OF MEDICINE
Graduated 1980 (46 years in practice)
Group practice The University Of Chicago Medical Center — 909 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations2 on file with Medicare

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