NPPES file of Aug 9, 2026

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 15 of 109.

CMS NPPES registry, file of Aug 9, 2026 · method · Verify with CMS →

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

  1. Katharine CarranzaBehavior Technician1295372357
  2. Maya CarranzaBehavior Technician1063308484
  3. Catherine Carreiro, PT, ATCPhysical Therapist1003960337
  4. Elizabeth CarrenoBehavior Technician1407312770
  5. Andrea CarreraClinical Social Worker1013890086
  6. Esther Carrera, LMFTMarriage & Family Therapist1003408097
  7. Grecia CarreraStudent in an Organized Health Care Education/Training Program1164398095
  8. Mark Vincent CarreraBehavior Technician1811672884
  9. Amanda Carrillo, LCSWClinical Social Worker1477804227
  10. Carrie Carrillo, PASurgical Physician Assistant1588872089
  11. Daisy CarrilloBehavior Technician1801352026
  12. Janet CarrilloBehavior Technician1982215661
  13. Jennifer Carroll, LMFTMental Health Counselor1982169280
  14. Allison Carson, O.T.R./LPediatric Occupational Therapist1699020230
  15. Danielle Carter, COTA/LOccupational Therapy Assistant1679093298
  16. Jeffery Carter, M.EDAddiction (Substance Use Disorder) Counselor1356895502
  17. June Carter, MSWCase Manager/Care Coordinator1326229089
  18. Kericia CarterAddiction (Substance Use Disorder) Counselor1295316859
  19. Malik CarterBehavior Technician1982595989
  20. Kevin Caruthers, COTA/LOccupational Therapy Assistant1194649525
  21. Karina CarvajalCase Manager/Care Coordinator1689997207
  22. Vivian CasanolaBehavior Technician1720837305
  23. Marisa CasasBehavior Technician1023575180
  24. Annette Casavalente, RPHPharmacist1528878782
  25. Jonathan CasillasBehavior Technician1366187379
  26. Angelica CastanedaStudent in an Organized Health Care Education/Training Program1164309803
  27. Angy CastanedaBehavior Technician1093549164
  28. Samantha CastanedaBehavior Technician1265049100
  29. Delfina CastelanStudent in an Organized Health Care Education/Training Program1861328767
  30. Alicia CastellonAthletic Trainer1770395774
  31. Arlene CastilloBehavior Technician1841950722
  32. Dulce CastilloBehavior Technician1831883891
  33. Jesse CastilloBehavior Technician1417542549
  34. Jocelyn CastilloBehavior Technician1437032125
  35. Juvenal CastilloProfessional Counselor1023642303
  36. Kevin CastilloPhysical Therapist1063293736
  37. Maria CastilloBehavior Technician1760944458
  38. Michael Castillo, 1-17-26709 BCBABehavior Analyst1841711041
  39. Elaine CastorBehavior Technician1588129415
  40. Jose CastorenaCommunity Health Worker1336546852
  41. Vicky CastorenaAddiction (Substance Use Disorder) Counselor1154883155
  42. Lillian Castrillo-JonesInterpreter1376330712
  43. Arlene CastroBehavior Analyst1992450969
  44. Caleb CastroBehavior Technician1386387280
  45. Camila CastroBehavior Technician1427806355
  46. Christa Castro, AMFTMarriage & Family Therapist1376111914
  47. Delfa CastroCase Manager/Care Coordinator1932640141
  48. Evelyn CastroBehavior Technician1861228215
  49. Fritzie CastroPediatric Occupational Therapist1003103524
  50. Haley Castro, PT, DPTPediatric Physical Therapist1821934043

The largest California cities

  1. Los Angeles69,537
  2. San Diego52,937
  3. San Francisco38,143
  4. Sacramento33,083
  5. San Jose20,925

All of California →

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.