Quick answers
- Does John H. O Neill Jr. accept Medicare assignment?
- Yes. Medicare's clinician data says John H. O Neill Jr. 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 John H. O Neill Jr. see?
- In 2024, CMS data shows 372 Original Medicare patients and 1,030 services for John H. O Neill Jr.. This counts Original Medicare only and measures volume, not quality.
- What is John H. O Neill Jr.'s NPI number?
- 1265445233. 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 John H. O Neill Jr., 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 | 372 |
|---|---|
| Services billed to Medicare | 1,030 |
| Different services or procedures | 9 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)671 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)139 services
- Hospital discharge day management, more than 30 minutes (99239)87 services
- Hospital discharge day management, 30 minutes or less (99238)63 services
- Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes (99231)37 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%
- Arthritis60%
- Chronic kidney disease56%
- Ischemic heart disease51%
- Diabetes47%
Hospitals where John H. O Neill Jr. works
Medicare's Facility Affiliation Data lists John H. O Neill Jr. 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.
- Christiana HospitalNewark, DE · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 080001
Practice locations
Addresses where John H. O Neill Jr. is enrolled with Medicare (CMS data updated October 2, 2026).
- 1401 Foulk RdWilmington, DE 19803
- 4755 Ogletown Stanton RdNewark, DE 19718
- 501 W 14th StWilmington, DE 19801
- 501 W 14th St Fl, 6 Cchs Infectious DiseaseWilmington, DE 19801 (302) 320‑1300
- 501 W 14th St Wilmington HospitalWilmington, DE 19801
Group practices
Medicare enrollment lists John H. O Neill Jr. as a member of this group (CMS data updated October 2, 2026).
- Christiana Care Health Services Inc1,483 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Wilmington
Clinicians with the same Medicare primary specialty in Wilmington, DE — not a recommendation.
Other clinicians in Christiana Care Health Services Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Des Moines University Of Osteopathic Medicine And Health Sciences |
| Graduation year | 1986 (40 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1265445233 |
| 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