Quick answers
- Does Chijoke H. Onyenwenyi accept Medicare assignment?
- Yes. Medicare's clinician data says Chijoke H. Onyenwenyi accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Chijoke H. Onyenwenyi see?
- In 2024, CMS data shows 605 Original Medicare patients and 2,650 services for Chijoke H. Onyenwenyi. This counts Original Medicare only and measures volume, not quality.
- What is Chijoke H. Onyenwenyi's NPI number?
- 1285941153. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Chijoke H. Onyenwenyi, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 605 |
|---|---|
| Services billed to Medicare | 2,650 |
| Different services or procedures | 41 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)649 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)365 services
- Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)254 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)203 services
- Dialysis services, 4 or more physician visits per month (20 years or older) (90960)178 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Chronic kidney disease75%
- Diabetes68%
- Heart failure66%
- Ischemic heart disease57%
Hospitals where Chijoke H. Onyenwenyi works
Medicare's Facility Affiliation Data lists Chijoke H. Onyenwenyi at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Advocate Christ Hospital & Medical CenterOak Lawn, IL · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 140208
- Northwestern Medicine Central Dupage HospitalWinfield, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140242
- OSF Little Company of Mary Medical CenterEvergreen Park, IL · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 140179
- Palos Community HospitalPalos Heights, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140062
Practice locations
Addresses where Chijoke H. Onyenwenyi is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 7; the Medicare profile lists all.
- 100 W 162nd St, Advocate Med Grp S HollandSouth Holland, IL 60473 (708) 730‑2200
- 12250 S Cicero Ave, Suite 112Alsip, IL 60803 (708) 371‑5308
- 16605 S 107th CtOrland Park, IL 60467 (708) 422‑7715
- 214 McHenry RdBuffalo Grove, IL 60089 (847) 459‑1160
- 4440 W 95th StOak Lawn, IL 60453
Group practices
Medicare enrollment lists Chijoke H. Onyenwenyi as a member of these groups (CMS data updated October 2, 2026).
- Advocate Health and Hospitals Corporation3,118 clinicians in the group
- Nephrology Associates of Northern Illinois Ltd117 clinicians in the group
- Southwest Nephrology Associates, S.C.13 clinicians in the group
Specialties
- Nephrologyprimary
- Internal Medicinealso
Other nephrologists in South Holland
Clinicians with the same Medicare primary specialty in South Holland, IL — not a recommendation.
Other clinicians in Advocate Health and Hospitals Corporation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2002 (24 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1285941153 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians