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RHEUMATOLOGY ASSOCIATES S.C.
NPI 1356431365
Internal Medicine - Rheumatology in Chicago, IL

Active since October 13, 2006CLIA 14D0666904 · Certificate of Compliance
1725 W HARRISON ST, SUITE 1039, CHICAGO, IL 60612(312) 226-8228(312) 226-5572 Get Directions Write a Review

NPPES record last updated: August 22, 2020. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Rheumatology Associates S.c. NPPES

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

RHEUMATOLOGY ASSOCIATES S.C. (NPI 1356431365) is a healthcare organization registered as a rheumatology in Chicago, Illinois and active in the NPI registry since October 2006. The organization holds a CLIA Certificate of Compliance certificate valid through April 4, 2027 and lists Robert S Katz, President, as its authorized official.

NPPES Registry Identity

NPI1356431365
Entity TypeOrganization
Primary Taxonomy207RR0500X
Legal Business NameRHEUMATOLOGY ASSOCIATES S.C.
Location Address1725 W HARRISON ST, SUITE 1039Chicago, IL 60612-3841
Mailing Address1725 W Harrison St, Suite 1039Chicago, IL 60612-3841 · (312) 226-8228 · Fax (312) 226-5572
Phone(312) 226-8228
Fax(312) 226-5572
Organization SubpartNo
Authorized OfficialRobert S KatzPresident · (312) 226-8228
Enumeration DateOctober 13, 2006
Last NPPES UpdateAugust 22, 2020
✔ NPI 1356431365 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · RheumatologyAllopathic & Osteopathic Physicians
Taxonomy Code207RR0500X
Definition
An internist who treats diseases of joints, muscle, bones and tendons. This specialist diagnoses and treats arthritis, back pain, muscle strains, common athletic injuries and collagen diseases.
1725 W HARRISON ST, Chicago, IL 60612
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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 and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Rheumatology Associates S.c. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

3

Medicare enrollment records show 3 clinicians reassign Medicare billing to Rheumatology Associates S.C., which bills Medicare for the services they deliver. Of these, 3 practice at this address. They are listed nearest first.

Clinicians, nearest first (3)

Robert Katz, M.D.
Rheumatology
NPI 1790875797
1725 W HARRISON ST STE 365
Chicago, IL 60612
(312) 226-8228
✔ PECOS✔ Accepts MedicareSame address
Alexandra Small, M.D.
Rheumatology
NPI 1356722292
1725 W HARRISON ST STE 365
Chicago, IL 60612
(312) 226-8228
✔ PECOS✔ Accepts MedicareSame address
Ben Small, MD
Rheumatology
NPI 1043656499
1725 W HARRISON ST STE 365
Chicago, IL 60612
(312) 226-8228
✔ PECOS✔ Accepts MedicareSame address

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

CLIA Laboratory Certificates CMS CLIA

Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.

Certificate of Compliance 14D0666904

Rheumatology Associates, Sc · Chicago, IL
Active · expires Apr 4, 2027
CLIA Number14D0666904
Laboratory TypePhysician Office
Certificate Effective DateApril 5, 2025
Certificate Expiration DateApril 4, 2027
Laboratory DirectorDr. Robert S. Katz MD
Laboratory Phone(312) 226-8228
Laboratory LocationRheumatology Associates, Sc1725 W Harrison St Ste 365, Chicago, IL 60612
CLIA data matches this NPI record on: Address Phone
This certificate is issued to a laboratory after an inspection that finds the laboratory to be in compliance with all applicable CLIA requirements.

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 Rheumatology Associates S.C.'s NPI number?

The NPI number for Rheumatology Associates S.C. is 1356431365. It was assigned to this organization in the NPPES registry on October 13, 2006.

Where is Rheumatology Associates S.C. located?

Rheumatology Associates S.C. is located at 1725 W Harrison St Suite 1039, Chicago, IL 60612. The listed phone number is (312) 226-8228.

What is Rheumatology Associates S.C.'s specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Rheumatology, with taxonomy code 207RR0500X.

Is Rheumatology Associates S.C. enrolled in Medicare?

Yes. Rheumatology Associates S.C. is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Rheumatology Associates S.C.?

According to the CMS Revalidation Reassignment List (October 2026 release), 3 clinicians, all in Rheumatology, reassign their Medicare billing to Rheumatology Associates S.C.. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Of these, 3 practice at this address. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Rheumatology Associates S.C. hold a CLIA laboratory certificate?

Yes. A Certificate of Compliance (number 14D0666904) is associated with this NPI, valid through April 4, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

When was this NPI record last updated?

The NPPES record for Rheumatology Associates S.C. was last updated on August 22, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.