NPPES file of Aug 9, 2026

Doctors and health care providers in O Fallon, IL

1,077 individual NPPES records list a practice address in O Fallon, 44th of 541 Illinois cities. The largest group is behavior technician: 295, 27% of the city's records, against 4% across Illinois. Page 15 of 22.

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

The 8 largest groups in O Fallon

Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.

O Fallon in Illinois

  • Rank in Illinois44th of 541 cities by records
  • Share of the state0.4% of Illinois's records
  • Specialties present25 or more taxonomy codes
  • Top three groups37.7% of all records
  • Behavior Technician rank4th of the 10 Illinois cities with the most

Compared with Illinois as a whole, O Fallon has 7× the state's share of behavior technician records and 0.25× its share of mental health counselor records.

Providers in O Fallon, alphabetically

  1. Maria OchiaiStudent in an Organized Health Care Education/Training Program1114736618
  2. Frederick Ochieng', M.D.Cardiovascular Disease Physician1497072854
  3. Ejikeme Odunukwe, M.D.Student in an Organized Health Care Education/Training Program1285438259
  4. Aaron Oge', DMDGeneral Practice Dentistry1417124058
  5. Nona Onderdonk, RBTBehavior Technician1396496162
  6. Umer Orakzai, M.D.Student in an Organized Health Care Education/Training Program1346186541
  7. Corey Osborne, D.C.Chiropractor1124040688
  8. Jayme Osterhout, OTR/LOccupational Therapist1114701653
  9. Rachel OttensmeierBehavior Technician1457015190
  10. Victoria PageBehavior Technician1164279626
  11. Amanda Pagel, M.S. CFY-SLPSpeech-Language Pathologist1639569213
  12. Summit Pandat, M.D.Clinical Cardiac Electrophysiology Physician1922454099
  13. Kacey Panyik, APN CNMAdvanced Practice Midwife1912366436
  14. Shannon Parimi, M.D.Pediatrics Physician1801215900
  15. Jaylen ParksBehavior Technician1659104446
  16. Kyle Parrilla, DCChiropractor1073092029
  17. Gerald PaskertPharmacist1962063800
  18. Jerica PatekSpeech-Language Pathologist1548890296
  19. Prabhudev PatilStudent in an Organized Health Care Education/Training Program1609571306
  20. Rhonda PearsonBehavior Technician1932711140
  21. Derek Pechacek, FNP-CFamily Nurse Practitioner1114356607
  22. Anthony Peck, DCChiropractor1376542480
  23. Michelle PedersenBehavior Technician1588192272
  24. Eugene Perkins, RPHPharmacist1508140328
  25. Kyriesha PerkinsBehavior Technician1568284891
  26. Cayla PerryBehavior Technician1336767474
  27. James Perulfi, D.C.Chiropractor1598885048
  28. Emily PetersonBehavior Technician1407785215
  29. Caitlin Pflasterer, M.ED., LCPCMental Health Counselor1174921084
  30. Elizabeth PhillipsBehavior Technician1871306704
  31. Shane PhillipsBehavior Technician1073199014
  32. Tiffany PhillipsBehavior Technician1982229324
  33. Wendy Phillips, LCSW, SSWSchool Social Worker1184847923
  34. Michael PieschelGerontology Clinical Nurse Specialist1639039936
  35. Emily Pike, MOT, OTR/LOccupational Therapist1881947158
  36. Sherry Pilkington, NPNurse Practitioner1962481770
  37. Jared Piper, DVMVeterinarian1053664045
  38. Kristen Pitts, DPT, PTPhysical Therapist1225495286
  39. Miranda Pogue, FNP-BCFamily Nurse Practitioner1427324656
  40. Sarah Poirot, NP-CNurse Practitioner1558800813
  41. Amillia Polk, LPNLicensed Practical Nurse1326960436
  42. Emily PollmanSpeech-Language Pathologist1790562767
  43. Sydney Pollmann, APRNFamily Nurse Practitioner1245032507
  44. Kevin Ponciroli, M.D.Pediatrics Physician1598776411
  45. Aurelia PoppPhysician Assistant1912527599
  46. Kimberly Portale, D.O.Obstetrics & Gynecology Physician1134482656
  47. Rece Portell, PAPhysician Assistant1841081379
  48. Amy Porter, MS, CCC-SLP/LSpeech-Language Pathologist1023521705
  49. Shayla Porter, RBTBehavior Technician1164157756
  50. Jordan PortnerSpeech-Language Pathologist1346993573

The largest Illinois cities

  1. Chicago63,379
  2. Springfield4,997
  3. Naperville4,634
  4. Peoria4,621
  5. Evanston4,013

All of Illinois →

How to read this directory

O Fallon, Illinois appears in the CMS National Plan and Provider Enumeration System with 1,077 registered healthcare providers spanning 25 or more distinct NUCC-taxonomy specialties. This count includes every individual clinician who has applied for an NPI and listed a practice address in O Fallon - physicians, dentists, nurse practitioners, physician assistants, chiropractors, physical therapists, optometrists, psychologists, podiatrists, and every other credentialed provider type CMS tracks. It does not measure hospital beds, urgent-care capacity, or whether a given clinic is accepting new patients; it measures the pool of professionals with current NPI enrollment and a O Fallon practice location on file. Every figure is drawn from the federal National Provider Identifier Registry (CMS NPPES) - more than 7 million providers, maintained since May 2007, with 2024 Medicare Part D data, and, according to CMS, can be searched, compared, and traced in our methodology.

The provider mix in O Fallon is weighted toward Behavior Technician (295 clinicians, followed by Speech-Language Pathologist with 67 and Family Medicine Physician with 44). That distribution reflects how NPPES records specialty: providers self-select a primary taxonomy code, so a family physician who also practices geriatrics will show up under whichever NUCC code they registered first. Relative to Illinois's population, O Fallon reports roughly 8.6 providers per 100,000 residents using the state-level denominator, which is a rough proxy rather than a precise access-to-care measurement; the true catchment area of any {cityName} clinician extends beyond the municipal boundary.

Of Illinois's most common specialties, Internal Medicine Physician is the most prominent one with no provider currently listing a O Fallon practice address, a coverage gap O Fallon patients typically fill by traveling to a larger nearby hub.

For O Fallon patients, this directory is most useful as a starting shortlist. Important: PlainDoctor is a directory of publicly available CMS government data, not a review site, a ranking, or medical advice. NPPES data is self-reported and refreshed monthly; call the practice directly to confirm the provider is still there, accepts your insurance, and is taking new patients.

For informational purposes only; this directory is not medical advice and not a substitute for checking a license. See also: how to find a doctor and how to verify one.

Common questions

How many doctors are in O Fallon, IL?

There are 1,077 registered healthcare providers in O Fallon, IL, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.

What are the most common medical specialties in O Fallon?

The most common specialties in O Fallon are Behavior Technician, Speech-Language Pathologist, Family Medicine Physician, Student in an Organized Health Care Education/Training Program, Behavior Analyst. Behavior Technician has the most providers with 295.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov). Records are self-reported registrations, not licenses.

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.