Quick answers
- Which hospitals does Eileen O'Halloran work at?
- Medicare's official clinician data lists Eileen O'Halloran at 3 hospitals: Mercy Hospital South, Mercy Hospital Springfield and Mercy Hospital St Louis. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Eileen O'Halloran see patients?
- Medicare's clinician data lists 4 practice locations, including Saint Louis, MO and Washington, MO. Call before your visit to confirm the address.
- What is Eileen O'Halloran's specialty?
- Medicare lists General Surgery as the primary specialty.
- Does Eileen O'Halloran accept Medicare assignment?
- Yes. Medicare's clinician data says Eileen O'Halloran 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 Eileen O'Halloran offer telehealth?
- Medicare's clinician data says Eileen O'Halloran offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Eileen O'Halloran?
- (314) 525-4440, as listed in official Medicare / NPI Registry data.
- What is Eileen O'Halloran's NPI number?
- 1447549571. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Eileen O'Halloran works
Medicare's Facility Affiliation Data lists Eileen O'Halloran at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mercy Hospital SouthSaint Louis, MO · Acute Care Hospital · CCN 260077
- Mercy Hospital SpringfieldSpringfield, MO · Acute Care Hospital · CCN 260065
- Mercy Hospital St LouisSaint Louis, MO · Acute Care Hospital · CCN 260020
Practice locations
Addresses where Eileen O'Halloran is enrolled with Medicare (CMS data updated 2026-10-02).
- 10050 Kennerly Rd, Suite 25200Saint Louis, MO 63128 (314) 525‑4440
- 607 S New Ballas Rd, 3100 Mercy Clinic Surgical Oncology DavSaint Louis, MO 63141 (314) 251‑1340
- 621 S New Ballas Rd, Suite 3005bSaint Louis, MO 63141 (314) 567‑5850
- 851 E 5th St, Suite 108Washington, MO 63090 (636) 861‑7870
Group practices
Medicare enrollment lists Eileen O'Halloran as a member of this group (CMS data updated 2026-10-02).
- Mercy Clinic Surgical Specialists LLC182 clinicians in the group
Specialties
- General Surgeryprimary
Other general surgeons in Saint Louis
Clinicians with the same Medicare primary specialty in Saint Louis, MO — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Loyola University Of Chicago, Stritch School Of Medicine |
| Graduation year | 2011 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1447549571 |
| 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