Quick answers
- Which hospitals does Caitlin Alonzo work at?
- Medicare's official clinician data lists Caitlin Alonzo at 3 hospitals: HSHS St Elizabeth's Hospital, St Joseph's Hospital and St Josephs Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Caitlin Alonzo see patients?
- Medicare's clinician data lists 1 practice location in O Fallon, IL. Call before your visit to confirm the address.
- What is Caitlin Alonzo's specialty?
- Medicare lists Nurse Practitioner as the primary specialty.
- Does Caitlin Alonzo accept Medicare assignment?
- Yes. Medicare's clinician data says Caitlin Alonzo 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.
- What is the phone number for Caitlin Alonzo?
- (618) 234-2120, as listed in official Medicare / NPI Registry data.
- What is Caitlin Alonzo's NPI number?
- 1083576243. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Caitlin Alonzo works
Medicare's Facility Affiliation Data lists Caitlin Alonzo at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- HSHS St Elizabeth's HospitalO Fallon, IL · Acute Care Hospital · CCN 140187
- St Joseph's HospitalHighland, IL · Critical Access Hospital · CCN 141336
- St Josephs HospitalBreese, IL · Acute Care Hospital · CCN 140145
Practice locations
Addresses where Caitlin Alonzo is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 Saint Elizabeth BlvdO Fallon, IL 62269 (618) 234‑2120
Group practices
Medicare enrollment lists Caitlin Alonzo as a member of this group (CMS data updated 2026-10-02).
- Cep America-Illinois Hospitalists, LLP196 clinicians in the group
Specialties
- Nurse Practitionerprimary
Other nurse practitioners in O Fallon
Clinicians with the same Medicare primary specialty in O Fallon, IL — not a recommendation.
Clinician information
| Graduation year | 2018 |
|---|---|
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1083576243 |
| 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