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 21 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. Chih Jen Wang, O.D.Optometrist1861443079
  2. Allison WashenkoPharmacist1821698432
  3. Kayla Waterman, MS, CCC-SLPSpeech-Language Pathologist1063930774
  4. Heather WatersonBehavior Technician1003403965
  5. Ashley WatschingerBehavior Technician1346899317
  6. Dominique Watson-Blake, RBTBehavior Technician1194361956
  7. Mya Watson-Blake, RBTBehavior Technician1205571130
  8. Deanna WeaverBehavior Analyst1043989320
  9. Kayla WeaverBehavior Technician1891317020
  10. Mandy Weaver, DOStudent in an Organized Health Care Education/Training Program1447102264
  11. Hannah Webber, MDFamily Medicine Physician1902460231
  12. J Weber, O.D.Optometrist1205845187
  13. Madisyn WebsterSocial Worker1134062953
  14. Bena Weeks, FNP-CFamily Nurse Practitioner1518356088
  15. Lorri WeeksBehavior Technician1235940032
  16. Donald Weimer, M.D.Orthopaedic Surgery Physician1932152980
  17. Jessica Weis, ODCorneal and Contact Management Optometrist1205406766
  18. Megan WellsBehavior Technician1467023234
  19. Shannon WellsBehavior Technician1427986413
  20. Madeline WesselmannBehavior Technician1104784016
  21. Abigail WestBehavior Technician1164184321
  22. Shonata West, APRNAcute Care Nurse Practitioner1316802556
  23. Mollie Wetstein, MDFamily Medicine Physician1710479761
  24. Kristin Wheeler, RPHPharmacist1932097722
  25. Stephanie Whisenand, COTA/LOccupational Therapy Assistant1336942861
  26. Katelyn Whitener, RNRegistered Nurse1659180438
  27. Nancy Wiebke, APRNAdult Health Nurse Practitioner1881639235
  28. Samantha Wiegand, ED.S., M.S.School Psychologist1841919701
  29. Patricia Wiesner, PTPhysical Therapist1144322256
  30. Taylor Wiggins, M.S. CCC-SLPSpeech-Language Pathologist1043938293
  31. Eric WileyBehavior Technician1346705944
  32. Brandi WilliamsBehavior Technician1841818903
  33. Camille Williams, M.D.Radiation Oncology Physician1649436510
  34. Christine WilliamsOccupational Therapy Assistant1821828435
  35. Dominique WilliamsBehavior Analyst1730742628
  36. Grace WilliamsBehavior Technician1922885284
  37. Jeffrey Williams, D.C.Chiropractor1306864137
  38. Madison Williams, BTBehavior Technician1083561278
  39. Porscha WilliamsBehavior Analyst1578185237
  40. Stephanie WilliamsBehavior Technician1952977902
  41. Amanda Wilson, OTR/LOccupational Therapist1376946293
  42. Dominique Wilson, MA, LCPC, CRCProfessional Counselor1407345192
  43. Tessa WilsonBehavior Technician1740835313
  44. Tremiya WinbushBehavior Technician1710592092
  45. Roxanne Winebaugh, DMDDentist1912524596
  46. Margaret Winkeler, RN, IBCLC, CEIMLactation Consultant (Registered Nurse)1295282085
  47. Laurean Winston, PA-CPhysician Assistant1790111490
  48. Jamie WintersSpeech-Language Pathologist1881200863
  49. Zachariah Wisnasky, RNRegistered Nurse1730044850
  50. Jacob Witt, M.D.Radiation Oncology Physician1891157871

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.