2026 data CMS NPPES NUCC Taxonomy

Doctors in O Fallon, IL

Compiled from official public sources by the PlainDoctor editorial team.

Active healthcare providers in O Fallon sourced from the CMS NPPES weekly file, no proprietary ratings, no editorial scores. NPI counts, specialty distribution, and primary practice addresses refreshed each release.

987
Providers
CMS NPPES-registered
20
Specialties
NUCC taxonomy codes
Behavior Technician
Top specialty
273 providers
Illinois
State
IL

987 healthcare providers across 20 specialties

O Fallon, Illinois appears in the CMS National Plan and Provider Enumeration System with 987 registered healthcare providers spanning 20 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 2023 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 (273 clinicians, followed by Speech-Language Pathologist with 68 and Student in an Organized Health Care Education/Training Program with 50). 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 7.9 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.

Within Illinois, O Fallon ranks #49 of 540 cities tracked by provider count, accounting for 0.4% of the state's registered providers. 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, searching by specialty narrows the 690-taxonomy roster to clinicians with the relevant training, and each provider page links to NPI, state licensing boards, and the NPPES registry for credential verification. 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, so listing details may be out of date; call the practice directly to confirm the provider is still there, accepts your insurance, and is taking new patients. Nothing on this page substitutes for consulting a licensed clinician about your personal health decisions.

987
Providers
20
Specialties
#49
of 540 IL cities
0.4%
of IL providers
7.9
Per 100K (state)

Which specialties are most common in O Fallon

Behavior Technician 273
Speech-Language Pathologist 68
Student in an Organized Health Care Education/Training Program 50
Behavior Analyst 39
Family Medicine Physician 37
Chiropractor 34
Pharmacist 28
Clinical Social Worker 27
Family Nurse Practitioner 25
Physician Assistant 24
Professional Counselor 23
Physical Therapist 22
Emergency Medicine Physician 20
Occupational Therapist 18
Certified Registered Nurse Anesthetist 15
Nurse Practitioner 15
Cardiovascular Disease Physician 15
Mental Health Counselor 14
General Practice Dentistry 13
Registered Nurse 12

Healthcare Providers (Page 5)

Name
Leslie Davis, MA,LCPC
Counselor
Morgan Delozier, DO
Family Medicine Physician
Rachael Demattei, APRN
Registered Nurse
Richard Derby, MD
Sports Medicine (Family Medicine) Physician
Jennifer Deschene, LMT
Massage Therapist
Rajeev Dewan, M.D.
Geriatric Medicine (Internal Medicine) Physician
Jennifer Dial
Behavior Technician
Andrew Dichsen, OTR/L
Physical Rehabilitation Occupational Therapist
Kristi Dieckmann, D.C., M.S.
Rehabilitation Chiropractor
Jamie Diekemper, RBT
Behavior Technician
Kelly Diekemper
Speech-Language Pathologist
Amanda Dillard, LCPC, NCC
School Counselor
Angela Dillick
Nurse's Aide
Katherine Dillon, LCSW
Clinical Social Worker
Danielle Ditterline
Behavior Technician
Elizabeth Divine
Behavior Technician
Sarah Dixon
Behavior Technician
Angie Dolosic
School Psychologist
Gwen Donley
Professional Counselor
Randall Dooley, MD
Urology Physician
Christina Dothager, M.D.
Obstetrics & Gynecology Physician
Jakia Douglas
Behavior Technician
Susan Drabing, FNP-BC
Family Nurse Practitioner
Dawn Drewes, APN
Family Nurse Practitioner
Vincent Duenas, MD
Family Medicine Physician
Victoria Dunahee
Behavior Analyst
Ella Duncan, LCSW
Clinical Social Worker
Bailey Durbin, RBT
Behavior Technician
Caitlyn Durfee
Behavior Technician
Sarah Durnell, FNP
Nurse Practitioner
Emily Dzugan
Behavior Analyst
Amanda Eapen
Behavior Technician
Joyce Eckerman, SLP
Speech-Language Pathologist
Bethany Edwards, RBT
Behavior Technician
Caroline Effinger
Behavior Technician
Samantha Eggemeyer
Behavior Technician
Kaylee Eidson
Behavior Technician
Kelli Eimer, OTR/L
Pediatric Occupational Therapist
Emma Ellington
Behavior Analyst
Molly Ellis
Behavior Technician
Mechelle Elosiebo, M.D.
Student in an Organized Health Care Education/Training Program
Abigail Ernst
Speech-Language Pathologist
David Ernst, O.D.
Optometrist
Tiffany Esposito, RBT
Behavior Technician
Cameron Evans, D.O.
Ophthalmology Physician
Clint Evans
Behavior Analyst
Carol Evaul, M.A., L.P.C.
Addiction (Substance Use Disorder) Counselor
Rick Fagan, LCPC
Professional Counselor
Kristen Fairbank
Behavior Technician
Matthew Falconer, OD
Optometrist

Nearby Cities in Illinois

Other Illinois cities with provider coverage in the CMS NPPES registry.

Compare specialties side-by-side →

Frequently Asked Questions

How many doctors are in O Fallon, IL?
There are 987 registered healthcare providers in O Fallon, IL, covering 20 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, Student in an Organized Health Care Education/Training Program, Behavior Analyst, Family Medicine Physician. Behavior Technician has the most providers with 273.

Provider data from CMS NPPES (download.cms.gov/nppes); specialty classification from NUCC Health Care Provider Taxonomy. PlainDoctor does not rate or rank providers. Methodology · About

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from CMS National Plan and Provider Enumeration System (NPPES). Consult a qualified professional before making decisions based on this data.

Compiled from official public sources by the PlainDoctor editorial team.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-20.