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

Brian O'Leary, MD

Individual provider Internal Medicine Physician · NPI 1295702439

Brian O'Leary, MD is an Internal Medicine in Naperville, Illinois. Graduated from Northwestern University Feinberg Medical School in 1985, 41 years ago. Practices with Dupage Medical Group Ltd, a 1,328-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Illinois.

Years since qualifying
41
Trained at
Northwestern University Feinberg Medical School
Licensed in
IL
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1964 Springbrook Square Dr Ste 104
Naperville, IL 60564-5949
Phone: (630) 946-2565
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 036073069 (IL)

Record details

NPI number1295702439
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedMarch 7, 2006
Last updated in NPPESSeptember 24, 2021
Certification dateSeptember 24, 2021
Mailing address1860 Paysphere Cir, Chicago, IL 60674-0018

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolNORTHWESTERN UNIVERSITY FEINBERG MEDICAL SCHOOL
Graduated 1985 (41 years in practice)
Group practice Dupage Medical Group Ltd — 1328 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

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