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DR. GREGORY O'NEAL CLARK M.D.
NPI 1053363952
Internal Medicine - Endocrinology, Diabetes & Metabolism in Buffalo Grove, IL

Active since May 17, 2006PECOS Enrolled
355 W DUNDEE RD STE 110, BUFFALO GROVE, IL 60089(847) 541-4878(847) 520-0500 Get Directions Write a Review

NPPES record last updated: July 26, 2023. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Dr. Gregory O'neal Clark M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. GREGORY O'NEAL CLARK M.D. (NPI 1053363952) is an individual endocrinology, diabetes & metabolism provider in Buffalo Grove, Illinois, licensed in Illinois (336.093729) and active in the NPI registry since May 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1053363952
Entity TypeIndividualMale
Primary Taxonomy207RE0101X
Provider Legal NameDR. GREGORY O'NEAL CLARKCredential: M.D.
Location Address355 W DUNDEE RD STE 110Buffalo Grove, IL 60089-3500
Mailing Address920 Grandview LnLake Forest, IL 60045-3914 · (443) 823-0583
Phone(847) 541-4878
Fax(847) 520-0500
Sole ProprietorYes
Enumeration DateMay 17, 2006
Last NPPES UpdateJuly 26, 2023
NPPES CertifiedJuly 26, 2023
✔ NPI 1053363952 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Endocrinology, Diabetes & MetabolismAllopathic & Osteopathic Physicians
Taxonomy Code207RE0101X
License✔ Licensed in IL · 336.093729
Definition
An internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with disorders such as diabetes, metabolic and nutritional disorders, obesity, pituitary diseases and menstrual and sexual problems.
355 W DUNDEE RD STE 110, Buffalo Grove, IL 60089
Open in Google Maps ↗

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Gregory O'neal Clark M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 60089 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$137.43 typical visit price
range $59.81 – $181.38
Typical copayment $34.35 (range $14.95 – $45.34)
Most-billed visit code 99204
Established Patient
$105.07 typical visit price
range $19.15 – $147.12
Typical copayment $26.26 (range $4.78 – $36.78)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 6

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

TOUCH OF HEALTH PHYSICIANS MANAGEMENT
Point of Service
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (847) 541-4878
SHALE MARKS LLC
Counselor (Addiction (Substance Use Disorder))
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (847) 337-1960
ADVANTAGE HEALTHCARE SPECIALISTS, LLC
Internal Medicine (Geriatric Medicine)
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (847) 337-1960
J I FRANK, MD, SC
Psychiatry & Neurology (Neurology)
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (773) 612-8399
OPPORTUNITY CHIROPRACTIC, INC.
Chiropractor
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (847) 305-1343
NORRIS INSTITUTE
Psychologist (Clinical)
355 W DUNDEE RD STE 110
BUFFALO GROVE, IL 60089
Lake County (224) 636-6333

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Gregory Clark's NPI number?

The NPI number for Gregory Clark is 1053363952. It was assigned to this individual provider in the NPPES registry on May 17, 2006.

Where is Gregory Clark located?

Gregory Clark practices at 355 W Dundee Rd Ste 110, Buffalo Grove, IL 60089. The listed phone number is (847) 541-4878.

What is Gregory Clark's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Endocrinology, Diabetes & Metabolism, with taxonomy code 207RE0101X.

Is Gregory Clark enrolled in Medicare?

Yes. Gregory Clark is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Gregory Clark was last updated on July 26, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.