Quick answers
- Which hospitals does Sean M. O'Neill work at?
- Medicare's official clinician data lists Sean M. O'Neill at 3 hospitals: Chelsea Hospital, Holland Hospital and University of Michigan Health System. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Sean M. O'Neill see patients?
- Medicare's clinician data lists 14 practice locations, including Chelsea, MI and Ann Arbor, MI. Call before your visit to confirm the address.
- What is Sean M. O'Neill's specialty?
- Medicare lists General Surgery as the primary specialty.
- Does Sean M. O'Neill accept Medicare assignment?
- Yes. Medicare's clinician data says Sean M. O'Neill accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- Does Sean M. O'Neill offer telehealth?
- Medicare's clinician data says Sean M. O'Neill offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Sean M. O'Neill?
- (734) 936-7175, as listed in official Medicare / NPI Registry data.
- What is Sean M. O'Neill's NPI number?
- 1720421191. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Sean M. O'Neill works
Medicare's Facility Affiliation Data lists Sean M. O'Neill at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Chelsea HospitalChelsea, MI · Acute Care Hospital · CCN 230259
- Holland HospitalHolland, MI · Acute Care Hospital · CCN 230072
- University of Michigan Health SystemAnn Arbor, MI · Acute Care Hospital · CCN 230046
Practice locations
Addresses where Sean M. O'Neill is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 14; the Medicare profile lists all.
- 14650 E Old US Hwy 12, Umhs Chelsea Pro BldgChelsea, MI 48118 (734) 936‑7175
- 1500 E Medical Ctr, Suite 0331Ann Arbor, MI 48109 (734) 936‑5738
- 1500 E Medical Ctr 2nd Floor Rec, Taubman CenterAnn Arbor, MI 48109 (734) 936‑5020
- 1500 E Medical Ctr DrAnn Arbor, MI 48109
- 1500 E Medical Ctr Dr 1st Fl, Taubman Ctr Rec DAnn Arbor, MI 48109 (734) 936‑4185
Group practices
Medicare enrollment lists Sean M. O'Neill as a member of this group (CMS data updated 2026-10-02).
- Regents of the University of Michigan3,346 clinicians in the group
Specialties
- General Surgeryprimary
Other general surgeons in Chelsea
Clinicians with the same Medicare primary specialty in Chelsea, MI — not a recommendation.
Clinician information
| Medical school | Northwestern University Feinberg Medical School |
|---|---|
| Graduation year | 2013 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1720421191 |
| 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 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- 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