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COOK RADIATION ONCOLOGY SC
NPI 1689953838
Radiology - Radiation Oncology in Chicago, IL

Active since August 05, 2011
2233 W. DIVISION STREET, CANCER CENTER, CHICAGO, IL 60622(312) 864-3838(312) 864-9295 Get Directions Write a Review

NPPES record last updated: September 24, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Cook Radiation Oncology Sc NPPES

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

COOK RADIATION ONCOLOGY SC (NPI 1689953838) is a healthcare organization registered as a radiation oncology in Chicago, Illinois and active in the NPI registry since August 2011. The organization maintains a secondary practice location in Chicago and lists Harish Vrajlal Thakrar, Owner, as its authorized official.

NPPES Registry Identity

NPI1689953838
Entity TypeOrganization
Primary Taxonomy2085R0001X
Legal Business NameCOOK RADIATION ONCOLOGY SC
Location Address2233 W. DIVISION STREET, CANCER CENTERChicago, IL 60622
Mailing AddressPo Box 9732Naperville, IL 60567-0732 · (312) 864-3838 · Fax (312) 864-9295
Phone(312) 864-3838
Fax(312) 864-9295
Organization SubpartNo
Authorized OfficialHarish Vrajlal ThakrarOwner · (312) 864-3838
Enumeration DateAugust 5, 2011
Last NPPES UpdateSeptember 24, 2020
NPPES CertifiedSeptember 23, 2020
✔ NPI 1689953838 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyRadiology · Radiation OncologyAllopathic & Osteopathic Physicians
Taxonomy Code2085R0001X
License✔ Licensed in IL · 036046368
Definition
A radiologist who deals with the therapeutic applications of radiant energy and its modifiers and the study and management of disease, especially malignant tumors.
2233 W. DIVISION STREET, Chicago, IL 60622
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Secondary Practice Location 1

Location 17435 W Talcott AveChicago, IL 60631-3707 · Phone (312) 864-3838 · Fax (312) 864-9295

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)

Cook Radiation Oncology Sc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

6

Medicare enrollment records show 6 clinicians reassign Medicare billing to Cook Radiation Oncology Sc, which bills Medicare for the services they deliver. Of these, 4 practice within 10 miles. They are listed nearest first.

Clinicians, nearest first (6)

Donthamsetti Seshagirirao, MD
Radiation Oncology
NPI 1508819186
2216 W THOMAS ST
Chicago, IL 60622
(312) 864-3838
✔ PECOS✔ Accepts Medicare0.1 mi
Ross Zeitlin
Radiation Oncology
NPI 1689051328
1901 W HARRISON ST STE LL-500
Chicago, IL 60612
(312) 864-3838
✔ PECOS✔ Accepts Medicare2.0 mi
Christian Olortegui, M.D.
Radiation Oncology
NPI 1033564018
1901 W HARRISON ST
Chicago, IL 60612
(312) 864-3838
✔ PECOS✔ Accepts Medicare2.0 mi
Anupama Thakrar, M.D.
Radiation Oncology
NPI 1396727608
1901 W. HARRISON SUITE LL-500
Chicago, IL 60612
(312) 864-3838
✔ PECOS✔ Accepts Medicare2.0 mi
Zaid Iftekaruddin, MD
Radiation Oncology
NPI 1437611761
4405 WEAVER PKWY
Warrenville, IL 60555
(630) 933-7811
✔ PECOS✔ Accepts Medicare25 mi
Naresh Jegadeesh, M.D.
Radiation Oncology
NPI 1669765103
1364 CLIFTON RD NE
Atlanta, GA 30322
(404) 727-5658
✔ PECOS✔ Accepts Medicare589 mi

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

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 Cook Radiation Oncology Sc's NPI number?

The NPI number for Cook Radiation Oncology Sc is 1689953838. It was assigned to this organization in the NPPES registry on August 5, 2011.

Where is Cook Radiation Oncology Sc located?

Cook Radiation Oncology Sc is located at 2233 W. Division Street Cancer Center, Chicago, IL 60622. The listed phone number is (312) 864-3838.

What is Cook Radiation Oncology Sc's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Radiation Oncology, with taxonomy code 2085R0001X.

Is Cook Radiation Oncology Sc enrolled in Medicare?

Yes. Cook Radiation Oncology Sc is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Cook Radiation Oncology Sc?

According to the CMS Revalidation Reassignment List (October 2026 release), 6 clinicians, all in Radiation Oncology, reassign their Medicare billing to Cook Radiation Oncology Sc. 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, 4 practice within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Cook Radiation Oncology Sc was last updated on September 24, 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.