John J. O'Brien, M.D.
Family Medicine Physician · O Fallon, MO
John J. O'Brien, M.D. is a family medicine physician with a practice address in O Fallon, Missouri, and NPI 1083689061, issued on Feb 22, 2006. Check the license (Missouri R3E76, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.
- Name
- John J. O'Brien
- Credential
- M.D.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- R3E76 MO
Self-reported in NPPES; status is on the state search - Practice location
- 2630 Highway K, O Fallon, MO 63368
- Phone
- (636) 240-5454
- Enumerated
- Feb 22, 2006
- Record last updated
- Feb 24, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (618) 980-5335
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 2,991 in Missouri → Look up another NPI →
Also registered at 2630 Highway K
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Katherine Clancy, FNPNurse Practitioner1568724284
- Amanda Heidemann, MDFamily Medicine Physician1043329105
- Stacey Hunt, FNPFamily Nurse Practitioner1558929471
- Jyoti Kulkarni, MDFamily Medicine Physician1649281668
- Timothy Moore, D.O.Family Medicine Physician1396762910
- Anjum Razzaque, M.D.Emergency Medicine Physician1962427229
Verify John J. O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
Search for license R3E76Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
96% fewer Medicare Part D claims than the average family medicine physician in 2024
149 Medicare Part D claims for 79 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims.
Most prescribed
- Atorvastatin Calcium13 claims
- Simvastatin11 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.
John J. O'Brien among 2,991 family medicine physician records in Missouri
John J. O'Brien, M.D. is one of 2,991 family medicine physician records with a practice address in Missouri. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 13% of them.
- NPI issued2006 · 13% of these records are older, 52% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileNo · 59% of these records are
- Record last updated2021 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
37 family medicine physician records list a practice address in O Fallon
They are 37 of the 1,225 NPPES records with a practice address in O Fallon, and 2,991 family medicine physician records in Missouri.
All 2,991 in Missouri → Every provider in O Fallon → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Matthew Beckerdite, MDO Fallon, MO 633681821062266
- Michael Engel, MDO Fallon, MO 633681861431983
- Van Hargraves, MDO Fallon, MO 633681255326385
- Amanda Heidemann, MDO Fallon, MO 633681043329105
- Jyoti Kulkarni, MDO Fallon, MO 633681649281668
- Sean McIntoshO Fallon, MO 633681700997731
- Timothy Moore, D.O.O Fallon, MO 633681396762910
- George Stachecki, M.D.O Fallon, MO 633681902916927
Common questions
What is John J. O'Brien, M.D.'s NPI number?
John J. O'Brien, M.D.'s National Provider Identifier (NPI) is 1083689061, issued on Feb 22, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John J. O'Brien, M.D. located?
The NPPES record lists a practice address at 2630 Highway K, O Fallon, MO, 63368. Phone: (636) 240-5454. Providers update this record themselves, so call before visiting.
How can I verify John J. O'Brien, M.D.'s license?
NPPES lists Missouri license number R3E76, 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 John J. O'Brien, M.D. prescribe under Medicare Part D?
In 2024, John J. O'Brien, M.D. had 149 Medicare Part D claims for 79 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions 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.
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.