Registry data as of Aug 27, 2026

Jeffrey Hallazgo, M.D.

Internal Medicine Physician · Fenton, MO

Jeffrey Hallazgo, M.D. is an internal medicine physician with a practice address in Fenton, Missouri, and NPI 1073538302, issued on Jul 13, 2006. Check the license (Missouri R4G27, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1073538302
Name
Jeffrey Hallazgo
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
R4G27 MO
Self-reported in NPPES; status is on the state search
Practice location
714 Gravois RD, Fenton, MO 63026
Phone
(636) 326-6100
Enumerated
Jul 13, 2006
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 714 Gravois RD

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

  1. Kristin Aubuchon, FNP-BCFamily Nurse Practitioner1093231151
  2. Joy Bittle, P.A.-CMedical Physician Assistant1184866246
  3. Vandana Dalton, M.D.Obstetrics & Gynecology Physician1508126889
  4. Diane Eschmann-Morie, MDPediatrics Physician1902910292
  5. Isabel Fernandez-Holtzman, MDPediatrics Physician1629182852
  6. Justin Hugo, M.D.Family Medicine Physician1104826098

Verify Jeffrey Hallazgo in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
    Search for license R4G27
    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
Open the Missouri 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.

2.3 times the Medicare Part D claims of the average internal medicine physician in 2024

7,181 Medicare Part D claims for 583 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 97 claims were for opioids.

  1. Jeffrey Hallazgo7,181
  2. Specialty average3,176

Most prescribed

  1. Atorvastatin Calcium539 claims
  2. Amlodipine Besylate387 claims
  3. Losartan Potassium308 claims
  4. Levothyroxine Sodium284 claims
  5. Lisinopril237 claims
  6. Simvastatin192 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Industry payments in 2024: $336.29

18 payments, mostly food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Jeffrey Hallazgo$336.29
  2. Specialty average$1,303.06

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through one group practice

  1. Mercy Clinic East CommunitiesCreve Coeur, MO

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

13 internal medicine physician records list a practice address in Fenton

They are 13 of the 493 NPPES records with a practice address in Fenton, and 2,604 internal medicine physician records in Missouri.

Other internal medicine physician records in Missouri

  1. Betty Abban, M.D.Springfield, MO1063893162
  2. Amer Abbas, MDSaint Louis, MO1508480666
  3. Fizza Abbas, MDSaint Louis, MO1588079230
  4. Marghoob Abbas, M.D.St Joseph, MO1588603781
  5. Muhammad Khalid Abbas, M.D.Springfield, MO1447877089
  6. Sundas Abbas, MDRichmond Heights, MO1649790486
  7. Hajira Abbasi, DOSaint Louis, MO1194036947
  8. Catey Abbott, DOSaint Louis, MO1699355347
  9. David Abbott, MDRichmond Heights, MO1568448850
  10. Wael Abduljaber, MDSaint Louis, MO1174101489

Common questions

What is Jeffrey Hallazgo, M.D.'s NPI number?

Jeffrey Hallazgo, M.D.'s National Provider Identifier (NPI) is 1073538302, issued on Jul 13, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Jeffrey Hallazgo, M.D. located?

The NPPES record lists a practice address at 714 Gravois RD, Fenton, MO, 63026. Phone: (636) 326-6100. Providers update this record themselves, so call before visiting.

How can I verify Jeffrey Hallazgo, M.D.'s license?

NPPES lists Missouri license number R4G27, as entered by the provider. Search the Missouri Board of Registration for the Healing Arts at https://www.fsmb.org/contact-a-state-medical-board/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Jeffrey Hallazgo, M.D. prescribe under Medicare Part D?

In 2024, Jeffrey Hallazgo, M.D. had 7,181 Medicare Part D claims for 583 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

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) 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 27, 2026.