DOCTORS UNLIMITED SERVICE CORPORATION
NPI 1265739643
Internal Medicine in Chicago, IL

Q: What is Doctors Unlimited Service Corporation's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Active since February 19, 2011

1750 E 87TH ST STE 109, CHICAGO, IL 60617(773) 933-9300(773) 933-9302 Get Directions Write a Review

NPPES record last updated: January 15, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jan 15, 2026, Nov 10, 2020 (2 updates tracked since 2020).

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About Doctors Unlimited Service Corporation NPPES

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

DOCTORS UNLIMITED SERVICE CORPORATION (NPI 1265739643), doing business as Integracare Clinic, is a healthcare organization registered as an internal medicine in Chicago, Illinois and active in the NPI registry since February 2011. The organization lists Otuonye Ezeribe Onyewuchi, President/ceo, as its authorized official.

NPPES Registry Identity

NPI1265739643

Entity TypeOrganization

Primary Taxonomy207R00000X

Legal Business NameDOCTORS UNLIMITED SERVICE CORPORATION

Location Address1750 E 87TH ST STE 109Chicago, IL 60617-2706

Mailing AddressPo Box 806112Chicago, IL 60680-4122 · (773) 933-9300 · Fax (773) 933-9302

Phone(773) 933-9300

Fax(773) 933-9302

Organization SubpartNo

Authorized OfficialOtuonye Ezeribe OnyewuchiPresident/ceo · (773) 933-9300

Enumeration DateFebruary 19, 2011

Last NPPES UpdateJanuary 15, 20262 updates tracked since enumeration

NPPES CertifiedJanuary 15, 2026

✔ NPI 1265739643 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207R00000X

License✔ Licensed in IL · 036118945

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

1750 E 87TH ST STE 109, Chicago, IL 60617

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Other Names 1

Doing Business AsIntegracare Clinic

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)

Doctors Unlimited Service Corporation is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 3 clinicians reassign Medicare billing to Doctors Unlimited Service Corporation, which bills Medicare for the services they deliver. Of these, 1 practice at this address. They are listed nearest first.

Clinicians, nearest first (3)

Otuonye Onyewuchi, MD, MPH

Internal Medicine

NPI 1538354295

1750 E 87TH ST STE 109
Chicago, IL 60617

(773) 933-9300

✔ PECOS✔ Accepts MedicareSame address

Oluseun Osinowo

Nurse Practitioner

NPI 1548614431

4850 N SAWYER AVE STE 1
Chicago, IL 60625

(872) 292-9958

✔ PECOS✔ Accepts Medicare17 mi

Victor Okamgba

Nurse Practitioner

NPI 1629434741

3075 BOOK RD STE 103
Naperville, IL 60567

(708) 873-9059

✔ PECOS✔ Accepts Medicare31 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 Doctors Unlimited Service Corporation's NPI number?

The NPI number for Doctors Unlimited Service Corporation is 1265739643. It was assigned to this organization in the NPPES registry on February 19, 2011. The provider is doing business as Integracare Clinic.

Where is Doctors Unlimited Service Corporation located?

Doctors Unlimited Service Corporation is located at 1750 E 87th St Ste 109, Chicago, IL 60617. The listed phone number is (773) 933-9300.

What is Doctors Unlimited Service Corporation's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Doctors Unlimited Service Corporation enrolled in Medicare?

Yes. Doctors Unlimited Service Corporation is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Doctors Unlimited Service Corporation?

According to the CMS Revalidation Reassignment List (October 2026 release), 3 clinicians reassign their Medicare billing to Doctors Unlimited Service Corporation, in Internal Medicine and Nurse Practitioner. 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, 1 practice at this address. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Doctors Unlimited Service Corporation was last updated on January 15, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 months 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.