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

Dr. Gregory O'Neal Clark, MD

Individual provider Endocrinology, Diabetes & Metabolism Physician · NPI 1053363952

Dr. Gregory O'Neal Clark, MD is an Endocrinology, Diabetes & Metabolism Physician in Buffalo Grove, Illinois. Practices as a sole proprietor. Licensed in Illinois.

Licensed in
IL
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

355 W Dundee Rd Ste 110
Buffalo Grove, IL 60089-3500
Phone: (847) 541-4878
Fax: (847) 520-0500
Show map & directions

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

Specialties & licences

Endocrinology, Diabetes & Metabolism Physician (primary) Taxonomy 207RE0101X · Licence 336.093729 (IL)

Record details

NPI number1053363952
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedMay 17, 2006
Last updated in NPPESJuly 26, 2023
Certification dateJuly 26, 2023

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