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 37 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
- Alyssa GrimaldiBehavior Technician1255152906
- Yesenia GrimaldoBehavior Technician1093309247
- Carol GrunbaumAddiction (Substance Use Disorder) Counselor1730781956
- Laura GuadarramaSchool Counselor1720951064
- Raul GuadarramaBehavior Technician1861221046
- Esther Guardado, P.A.CPhysician Assistant1073794152
- Sandhya Gudapati, M.D.Psychiatry Physician1962625384
- Denise GuerraBehavior Technician1538826599
- Alejandra GuerreroCase Manager/Care Coordinator1679945471
- Anthony GuerreroMarriage & Family Therapist1982914024
- Christian GuerreroBehavior Technician1669931234
- Daniel GuerreroRegistered Nurse1497316350
- Estevan GuerreroBehavior Technician1770366460
- Jenna Guest, SLPSpeech-Language Pathologist1124892476
- Eunice GuevaraSocial Worker1700547593
- Maria GuevaraBehavior Technician1396491361
- Stephen GuevaraRehabilitation Practitioner1497113112
- Rose-Ann GuevarraPhysician Assistant1154889327
- Anne Leah GuiaStudent in an Organized Health Care Education/Training Program1124799259
- James GuidangenStudent in an Organized Health Care Education/Training Program1891112470
- Marcus GuillenBehavior Technician1558241042
- Monica GuillermoBehavior Technician1558219337
- Evelyn GuilletBehavior Technician1144908211
- Gordon Gunn, MDGynecology Physician1194829184
- Brian Gunzelman, PT, DPTPhysical Therapist1023473717
- Tony GuoBehavior Technician1053062471
- Manmohan Gursahani, MDUrology Physician1720042336
- Dwane Gurung, M.A.Pediatric Occupational Therapist1215879085
- Patricia Gusti, DDSGeneral Practice Dentistry1740578467
- Tanya GustinMarriage & Family Therapist1063393676
- Alfredo GutierrezBehavior Technician1013779396
- Andrea GutierrezBehavior Technician1437967031
- Andrew GutierrezMental Health Counselor1871070516
- Brian GutierrezBehavior Technician1538820238
- Elvira GutierrezBehavior Technician1649843244
- Erica GutierrezBehavior Technician1326920745
- Kareen GutierrezStudent in an Organized Health Care Education/Training Program1801651468
- Linda GutierrezBehavior Technician1598498594
- Marastella GutierrezStudent in an Organized Health Care Education/Training Program1619300183
- Maria GutierrezBehavior Technician1770237638
- Matthew Allen GutierrezStudent in an Organized Health Care Education/Training Program1831991660
- Maximiliano GutierrezBehavior Technician1770049553
- Rebecca GutierrezBehavior Technician1376308262
- Sade GutierrezBehavior Technician1497568760
- Stephanie GutierrezBehavior Technician1245096643
- Valerie Gutierrez, B.A.Rehabilitation Practitioner1760619985
- Belen Gutierrez BarobioBehavior Technician1205596152
- Cristina Gutierrez VillavicencioBehavior Technician1295487627
- Connor Gutierrez-RayBehavior Technician1750119145
- Brian GuzmanAddiction (Substance Use Disorder) Counselor1801609938
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.