Iheanyichukwu Aja-Onu, MD

Medicare activity in 2024

Official CMS public-use data for Iheanyichukwu Aja-Onu, 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.

Most frequent services

1. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)5,406 services
2. Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)854 services
3. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)264 services
4. Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)142 services
5. Insertion of stomach tube using a flexible endoscope (43246)70 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%
• Diabetes67%
• Arthritis55%
• Ischemic heart disease55%
• Chronic kidney disease53%

Hospitals where Iheanyichukwu Aja-Onu works

Medicare's Facility Affiliation Data lists Iheanyichukwu Aja-Onu 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.

• Mercy Medical CenterRockville Centre, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330259
• Mount Sinai South NassauOceanside, NY · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 330198
• St John's Episcopal Hospital at South ShoreFar Rockaway, NY · Acute Care Hospital · Medicare rating: 1 of 5 stars · Emergency services: listed by Medicare · CCN 330395

Practice locations

Addresses where Iheanyichukwu Aja-Onu is enrolled with Medicare (CMS data updated October 2, 2026).

• 3 N Main StFreeport, NY 11520 (516) 623‑5076
• 327 Beach 19th StFar Rockaway, NY 11691 (516) 623‑5076

Specialties

• Gastroenterologyprimary
• Internal Medicinealso

Find other Gastroenterology doctors in New York →

Other gastroenterologists in New York

Clinicians with the same Medicare primary specialty in New York — not a recommendation.

• Harold L. Lipsky, MD
• Amy L. Lazzarini, MD
• Dhiren C. Mehta, MD
• Daniel G. Jamorabo, MD
• Ian J. Cohen, MD
• Herman Tessler, MD
• Michael P. Krumholz, MD
• Ariel Bar-Mashiah, MD

All gastroenterologists in New York →

Clinician information

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

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians