NPI Portal NPI Lookup & Verification

Type 2 · Organization ✓ Active NPI ✓ Valid NPI checksum

Aaron Greenspan, M.D.

Family Medicine Physician in Chicago, IL · enumerated 2007 · authorized official Aaron Greenspan, Medical Director.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1699897199

Verified

See something wrong? Report a correction

Registry record

Entity type Organization (Type 2)
Legal business name Aaron Greenspan, M.D.
Practice address 850 W Irving Park Rd, Chicago, IL, 60613
Phone (773) 525-6780
Enumeration date Apr 4, 2007
Last updated in NPPES Dec 2, 2008

Taxonomy & classification

207Q00000X Family Medicine Physician Allopathic & Osteopathic Physicians · License 036101234 (IL) Primary

Authorized official

Name Aaron Greenspan
Title Medical Director
Phone (847) 897-5995

Other identifiers

Identifier Type State Issuer
036101234 Medicaid IL -

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What type of organization is Aaron Greenspan, M.D.?
Aaron Greenspan, M.D. is registered in NPPES as a Family Medicine Physician (its primary provider taxonomy).
What is a Type 2 NPI?
A Type 2 NPI identifies an organization (group practice, hospital, pharmacy, lab), while Type 1 NPIs identify individual providers. Organizations bill under their Type 2 NPI.

Providers at this address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2008-12-02.