NPPES file of Aug 9, 2026

Caitlin Alonzo

Nurse Practitioner · O Fallon, IL

Caitlin Alonzo is a nurse practitioner with a practice address in O Fallon, Illinois, and NPI 1083576243, issued on Nov 26, 2025. Check the license (Illinois 209034125, as entered in NPPES) with the Illinois board that licenses this profession; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1083576243
Name
Caitlin Alonzo
Primary taxonomy
Nurse Practitioner 363L00000X
License numbers
209034125 IL
2025008810 MO
Self-reported in NPPES; status is on the state search
Practice location
1 Saint Elizabeth Blvd, O Fallon, IL 62269
Phone
(618) 234-2120
Enumerated
Nov 26, 2025
Record last updated
Mar 23, 2026
Medicare enrollment
Enrolled (PECOS I20260312002165); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest nurse practitioner records → All 4,892 in Illinois → Look up another NPI →

Also registered at 1 Saint Elizabeth Blvd

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Justin Baecht, CRNACertified Registered Nurse Anesthetist1801034491
  2. Leah Baecht, DNP, CRNA, APRNCertified Registered Nurse Anesthetist1275831273
  3. Gregory Bray-Stanley, MDAnesthesiology Physician1902836679
  4. Gage Buness, DOFamily Medicine Physician1881449635
  5. Amanda BurgesenCertified Registered Nurse Anesthetist1568084903
  6. Tessa Butt, PHARMDPharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1962202036

Verify Caitlin Alonzo in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Illinois board licenses this profession
    Search for license 209034125    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the Illinois license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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Bills Medicare through one group practice

  1. Cep America-Illinois Hospitalists, LLPO Fallon, IL

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Caitlin Alonzo among 4,892 nurse practitioner records in Illinois

Caitlin Alonzo is one of 4,892 nurse practitioner records with a practice address in Illinois. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2025, is newer than 92% of them.

  • NPI issued2025 · 92% of these records are older, 2% newer
  • In a Medicare fileYes · 81% of these records are
  • In the CMS Doctors and Clinicians fileYes · 69% of these records are
  • Graduated2018 · median 2018 among the 3,389 with a school on file
  • Record last updated2026 · 36% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363L00000X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

19 nurse practitioner records list a practice address in O Fallon

They are 19 of the 1,077 NPPES records with a practice address in O Fallon, and 4,892 nurse practitioner records in Illinois.

All 4,892 in Illinois → Every provider in O Fallon → Nurse Practitioner nationwide →

The 8 nurse practitioner records with the nearest ZIP codes

  1. Bethany Bowen, FNPShiloh, IL 622691609293372
  2. Kimberly Burgess, AGNP-CO Fallon, IL 622691164956066
  3. Kelly Evans, FNPShiloh, IL 622691508341181
  4. Marianne GuthrieO Fallon, IL 622691609313758
  5. Charissa Holesko, ANPO Fallon, IL 622691619343274
  6. Jodi Jany, AGNPO Fallon, IL 622691811357833
  7. Katy LorenzoO Fallon, IL 622691205348133
  8. Sherry Pilkington, NPO Fallon, IL 622691962481770

Common questions

What is Caitlin Alonzo's NPI number?

Caitlin Alonzo's National Provider Identifier (NPI) is 1083576243, issued on Nov 26, 2025. An NPI identifies a provider in billing; it is not a license.

Where is Caitlin Alonzo located?

The NPPES record lists a practice address at 1 Saint Elizabeth Blvd, O Fallon, IL, 62269. Phone: (618) 234-2120. Providers update this record themselves, so call before visiting.

How can I verify Caitlin Alonzo's license?

NPPES lists Illinois license number 209034125, as entered by the provider. Search the Illinois board that licenses this profession; the NPPES record confirms identity only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.