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.
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
- Maria OchiaiStudent in an Organized Health Care Education/Training Program1114736618
- Frederick Ochieng', M.D.Cardiovascular Disease Physician1497072854
- Ejikeme Odunukwe, M.D.Student in an Organized Health Care Education/Training Program1285438259
- Aaron Oge', DMDGeneral Practice Dentistry1417124058
- Nona Onderdonk, RBTBehavior Technician1396496162
- Umer Orakzai, M.D.Student in an Organized Health Care Education/Training Program1346186541
- Corey Osborne, D.C.Chiropractor1124040688
- Jayme Osterhout, OTR/LOccupational Therapist1114701653
- Rachel OttensmeierBehavior Technician1457015190
- Victoria PageBehavior Technician1164279626
- Amanda Pagel, M.S. CFY-SLPSpeech-Language Pathologist1639569213
- Summit Pandat, M.D.Clinical Cardiac Electrophysiology Physician1922454099
- Kacey Panyik, APN CNMAdvanced Practice Midwife1912366436
- Shannon Parimi, M.D.Pediatrics Physician1801215900
- Jaylen ParksBehavior Technician1659104446
- Kyle Parrilla, DCChiropractor1073092029
- Gerald PaskertPharmacist1962063800
- Jerica PatekSpeech-Language Pathologist1548890296
- Prabhudev PatilStudent in an Organized Health Care Education/Training Program1609571306
- Rhonda PearsonBehavior Technician1932711140
- Derek Pechacek, FNP-CFamily Nurse Practitioner1114356607
- Anthony Peck, DCChiropractor1376542480
- Michelle PedersenBehavior Technician1588192272
- Eugene Perkins, RPHPharmacist1508140328
- Kyriesha PerkinsBehavior Technician1568284891
- Cayla PerryBehavior Technician1336767474
- James Perulfi, D.C.Chiropractor1598885048
- Emily PetersonBehavior Technician1407785215
- Caitlin Pflasterer, M.ED., LCPCMental Health Counselor1174921084
- Elizabeth PhillipsBehavior Technician1871306704
- Shane PhillipsBehavior Technician1073199014
- Tiffany PhillipsBehavior Technician1982229324
- Wendy Phillips, LCSW, SSWSchool Social Worker1184847923
- Michael PieschelGerontology Clinical Nurse Specialist1639039936
- Emily Pike, MOT, OTR/LOccupational Therapist1881947158
- Sherry Pilkington, NPNurse Practitioner1962481770
- Jared Piper, DVMVeterinarian1053664045
- Kristen Pitts, DPT, PTPhysical Therapist1225495286
- Miranda Pogue, FNP-BCFamily Nurse Practitioner1427324656
- Sarah Poirot, NP-CNurse Practitioner1558800813
- Amillia Polk, LPNLicensed Practical Nurse1326960436
- Emily PollmanSpeech-Language Pathologist1790562767
- Sydney Pollmann, APRNFamily Nurse Practitioner1245032507
- Kevin Ponciroli, M.D.Pediatrics Physician1598776411
- Aurelia PoppPhysician Assistant1912527599
- Kimberly Portale, D.O.Obstetrics & Gynecology Physician1134482656
- Rece Portell, PAPhysician Assistant1841081379
- Amy Porter, MS, CCC-SLP/LSpeech-Language Pathologist1023521705
- Shayla Porter, RBTBehavior Technician1164157756
- Jordan PortnerSpeech-Language Pathologist1346993573
The largest Illinois cities
- Chicago63,379
- Springfield4,997
- Naperville4,634
- Peoria4,621
- Evanston4,013
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.