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 12 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. Jessica LortsOccupational Therapist1326891052
  2. Craig Lotz, PSYD, LCPClinical Psychologist1194879288
  3. Alexandria LovellStudent in an Organized Health Care Education/Training Program1902665466
  4. Nicole Lowrey, MD, PHDOphthalmology Physician1356902381
  5. Shae LowrySpeech-Language Pathologist1346768751
  6. Ashley Luberda, RBTBehavior Analyst1659014306
  7. Alicia Luechtefeld, M.S. CCC-SLPSpeech-Language Pathologist1508911991
  8. Anne Lueken, DPTPhysical Therapist1487403713
  9. Siyan Lumas, ED. SDevelopmental Therapist1346639374
  10. James Lundy, MDFamily Medicine Physician1245287085
  11. Taylor'Jode LusterBehavior Technician1831730266
  12. Kelsey LylesBehavior Technician1518554245
  13. Laura LynchBehavior Technician1427643527
  14. Kayla LynnBehavior Technician1043182793
  15. Bassam Maalouf, M.D.Hematology & Oncology Physician1720173438
  16. Abigail MackinBehavior Technician1548188170
  17. Mark Madder, DMDDentist1750398442
  18. Zachary Madej, PHARMDPharmacist1508381955
  19. Danielle MaggioBehavior Analyst1255830790
  20. Carol Makarewicz, RPHPharmacist1124628946
  21. Gabriele Malone, RBTBehavior Technician1750080479
  22. Angela MangumBehavior Analyst1821598293
  23. Angela Mann, RNC-OB, IBCLCLactation Consultant (Registered Nurse)1437738465
  24. Sarah MannixPhysician Assistant1750979464
  25. Jami Mannle, FNP-BCFamily Nurse Practitioner1184857674
  26. Crystal Manse, M.D.Internal Medicine Physician1366702870
  27. Johnathan Marchbanks, MSWClinical Social Worker1740802941
  28. Alexandria Marion, RBTBehavior Technician1548806490
  29. Whitney Marlow, M.D.Ophthalmology Physician1952783235
  30. Scott Marrus, MDCardiovascular Disease Physician1063578284
  31. Jacob Marshall, M.D.Family Medicine Physician1922081249
  32. Kellee Marshall, RD, LDRegistered Dietitian1679716476
  33. Montina MarshallDay Training/Habilitation Specialist1386133726
  34. Jennifer Martens, FNPFamily Nurse Practitioner1336659523
  35. Lance Martin, DMDGeneral Practice Dentistry1326215484
  36. Dawn MasseyBehavior Technician1407604689
  37. Erin Matos, BS, MS, CCC-SLP/LSpeech-Language Pathologist1760900427
  38. Gregory Maue, DCChiropractor1588150114
  39. Rosalie MaulSpeech-Language Pathologist1023535408
  40. Savannah MaySpeech-Language Pathologist1316718836
  41. Brianna Mayo, D.P.T.Physical Therapist1326399643
  42. Lori McAllister, LCPCProfessional Counselor1245495100
  43. Nicole McBride, PHARMDPharmacist1285916965
  44. Abriel McCabe, RBTBehavior Technician1578309530
  45. Destiny McCain, LCPCProfessional Counselor1780169995
  46. David McCarthy, MDFamily Medicine Physician1346242799
  47. Kevin McCarthy, M.D.Orthopaedic Surgery Physician1356579684
  48. Todd McClew, CRNACertified Registered Nurse Anesthetist1790764686
  49. Lori McCormickDevelopmental Therapist1043772528
  50. Jessica McDaniel, MA LPCMental Health Counselor1316423981

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.