Doctors and health care providers in Fullerton, CA
5,437 individual NPPES records list a practice address in Fullerton, 26th of 812 California cities. The largest group is behavior technician: 2,130, 39% of the city's records, against 18% across California. Page 25 of 109.
The 8 largest groups in Fullerton
Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.
Fullerton in California
- Rank in California26th of 812 cities by records
- Share of the state0.6% of California's records
- Specialties present25 or more taxonomy codes
- Top three groups49% of all records
Compared with California as a whole, Fullerton has 14.3× the state's share of pediatric occupational therapist records and 0.37× its share of family medicine physician records.
Providers in Fullerton, alphabetically
- Danny DiazBehavior Technician1972489342
- Elizabeth DiazBehavior Technician1912530098
- Guadalupe DiazCase Manager/Care Coordinator1366094948
- Lorenzo DiazBehavior Technician1114679529
- Madisen Diaz, DCChiropractor1851253934
- Martin Diaz, BABehavior Technician1447717186
- Michelle DiazBehavior Technician1598582223
- Sadie DiazBehavior Technician1205544558
- Samantha DiazBehavior Technician1437942760
- Stephanie DiazBehavior Technician1225790603
- Veronica DiazBehavior Technician1134755739
- Shiname Diaz-YangBehavior Technician1588444020
- Nancy Dibenedetto, MFABehavior Technician1649835091
- Joshua Dieterman, PMHNPPsychiatric/Mental Health Nurse Practitioner1760234892
- Lauren DigisonBehavior Technician1184580698
- Noell DillMarriage & Family Therapist1265250849
- Rebekah DillerBehavior Technician1356094627
- Mike DimmittCase Manager/Care Coordinator1316251515
- Anh DinhBehavior Technician1467275461
- Luke DinhBehavior Technician1114793528
- Michael DinhBehavior Technician1457818650
- Nathan DinhBehavior Technician1851146344
- Steven DinhBehavior Technician1851168934
- Maria Diosdado, NPFamily Nurse Practitioner1700628385
- Dhanya Divakaran, D.D.S.General Practice Dentistry1437599263
- Anthony-Tu DoFamily Medicine Physician1154070910
- Jocelyn DoStudent in an Organized Health Care Education/Training Program1275452252
- Son Do, M.DGeneral Practice Physician1295855815
- Son Do, M.D.Family Medicine Physician1184284168
- Tyler DoPharmacist1841014859
- Uyen DoAssistant Behavior Analyst1407545544
- Wynne DoPharmacist1811142896
- Lien Doan, M.D.Family Medicine Physician1912909698
- Minh DoanBehavior Technician1528873924
- Nina DoanPediatric Occupational Therapist1538083829
- Yvonne DoanMental Health Counselor1487796025
- Leslie Doi, MDDiagnostic Radiology Physician1740386366
- Robert DolanSurgery Physician1710307236
- Dechen Dolkar, MDRadiation Oncology Physician1861475683
- Dulce DominguezBehavior Technician1104550144
- Ashley DompierStudent in an Organized Health Care Education/Training Program1164852570
- Melissa DoolingLicensed Vocational Nurse1710435870
- Jovanna DoradoStudent in an Organized Health Care Education/Training Program1043873094
- Bailey Doran, RDRegistered Dietitian1003709023
- Michael DorattBehavior Technician1447012398
- Kylie DornbushBehavior Technician1083308621
- Helena DotsonBehavior Technician1295435063
- Xiaoli Dou, LVNLicensed Vocational Nurse1124304100
- Thomas Dougherty, M.D.Endocrinology, Diabetes & Metabolism Physician1699712232
- Jackie DouriganBehavior Technician1811647050
The largest California cities
- Los Angeles69,537
- San Diego52,937
- San Francisco38,143
- Sacramento33,083
- San Jose20,925
How to read this directory
Fullerton, California appears in the CMS National Plan and Provider Enumeration System with 5,437 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 Fullerton - 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 Fullerton 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 Fullerton is weighted toward Behavior Technician (2,130 clinicians, followed by Student in an Organized Health Care Education/Training Program with 269 and Marriage & Family Therapist with 263). 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 California's population, Fullerton reports roughly 14 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.
For Fullerton 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 Fullerton, CA?
There are 5,437 registered healthcare providers in Fullerton, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.
What are the most common medical specialties in Fullerton?
The most common specialties in Fullerton are Behavior Technician, Student in an Organized Health Care Education/Training Program, Marriage & Family Therapist, Pharmacist, Pediatric Occupational Therapist. Behavior Technician has the most providers with 2,130.
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.