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 18 of 22.

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

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

The 8 largest groups in O Fallon

  1. Behavior Technician295
  2. Speech-Language Pathologist67
  3. Family Medicine Physician44
  4. Students in training43
  5. Behavior Analyst43
  6. Chiropractor35
  7. Family Nurse Practitioner32
  8. Pharmacist31

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. Sydney Seelhoefer, DPTPhysical Therapist1730939026
  2. Nathan Seigrist, DOGeneral Practice Physician1780382465
  3. Adrian SerranoBehavior Technician1093643074
  4. Shelly Severns, DCChiropractor1699062661
  5. Salsapela Shaban, MDStudent in an Organized Health Care Education/Training Program1063351872
  6. Anam ShabbirStudent in an Organized Health Care Education/Training Program1275238321
  7. Jaynie ShaferSpeech-Language Pathologist1790333771
  8. Atul Shah, M.D.Cardiovascular Disease Physician1215965660
  9. Muhammad Sheikh, M.D.Interventional Cardiology Physician1194107524
  10. David Shervin, M.D.Orthopaedic Surgery Physician1366882227
  11. Ashley Shewmake, RBTBehavior Technician1851937619
  12. Spencer ShollPhysician Assistant1427805258
  13. Amardeep Shrestha, M.D.Internal Medicine Physician1730490525
  14. Nelson Shreve, MDSports Medicine (Family Medicine) Physician1720541527
  15. Brianna Shumpert, RNInpatient Obstetric Registered Nurse1437908043
  16. Ata Siddiqui, M.D.Anesthesiology Physician1043206618
  17. Tracy Sides, RBTBehavior Technician1598301442
  18. Amy Signore, DNP, RNEmergency Registered Nurse1639022932
  19. Sabrina Silvestri-BraumanStudent in an Organized Health Care Education/Training Program1710746367
  20. Ellen Simmons, M.S., CCC-SLPSpeech-Language Pathologist1083065551
  21. Stephanie Simpson, D.O.Hospitalist Physician1598183378
  22. Bonnie Singletary, M.ED., CCC-SLPSpeech-Language Pathologist1588771943
  23. Maya SingletaryBehavior Technician1326977125
  24. Arthur Sippo, M.D.Emergency Medicine Physician1023042165
  25. Abigail Skinner, DPTPhysical Therapist1386578037
  26. Renata Sledge, LCSWClinical Social Worker1194342170
  27. Julie Smirl, PHD, LCPCProfessional Counselor1457556672
  28. Alexandra SmithBehavior Analyst1033728167
  29. Allison Smith, MSN, PMHNP-BCPsychiatric/Mental Health Nurse Practitioner1821805011
  30. Angela Smith, LPCProfessional Counselor1366288037
  31. Arthur Smith, MDGynecology Physician1962497461
  32. Ashley SmithAttendant Care Provider1619681129
  33. Chiquita SmithClinical Social Worker1760274377
  34. Darionne Smith, LCPCProfessional Counselor1235827965
  35. Jennifer Smith, MDEmergency Medicine Physician1396366811
  36. Jennifer SmithBehavior Technician1952220170
  37. Jolita Smith, RBTBehavior Technician1992489496
  38. Kristin SmithSocial Worker1740023308
  39. Latisha Smith, ED.S.School Psychologist1134633993
  40. Macee Smith, CNPNurse Practitioner1467028019
  41. Tayler SmithBehavior Technician1225866148
  42. Brian Sneath, DMDDentist1346733540
  43. Ralph Spafford, P.A.-CMedical Physician Assistant1043446008
  44. Jamie SparksStudent in an Organized Health Care Education/Training Program1538390190
  45. Skyler Sparks, DCChiropractor1609723923
  46. Nikia Spates, RBTBehavior Technician1760028526
  47. Andrea StaffordPharmacist1184446841
  48. Robert StanleyBehavior Technician1790375749
  49. Ross Stanton, MD, JD, MPHFamily Medicine Physician1831710631
  50. Molly Stark, RPHPharmacist1528700176

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.