NPPES file of Aug 9, 2026

Doctors and health care providers in Lancaster, CA

4,273 individual NPPES records list a practice address in Lancaster, 49th of 812 California cities. The largest group is behavior technician: 436, 10% of the city's records, against 18% across California. Page 58 of 86.

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

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Lancaster in California

  • Rank in California49th of 812 cities by records
  • Share of the state0.4% of California's records
  • Specialties present25 or more taxonomy codes
  • Top three groups24.6% of all records

Compared with California as a whole, Lancaster has 4.5× the state's share of peer specialist records and 0.56× its share of physical therapist records.

Providers in Lancaster, alphabetically

  1. Merilyn OchoaClinical Social Worker1710481668
  2. Swanhilda Ochoa, LMFTMarriage & Family Therapist1023353398
  3. Colin OdeaBehavior Technician1962210831
  4. Russell Odono, MDAdult Reconstructive Orthopaedic Surgery Physician1194045450
  5. Ebenezer Odunusi, M.D.Pediatrics Physician1891728663
  6. Alexander OfuonyeRehabilitation Practitioner1063233823
  7. Joseph Ogbonnaya, REGISTERED NURSEAdult Psychiatric/Mental Health Registered Nurse1912565029
  8. Ayesha Ogle, NPAdult Health Nurse Practitioner1578706404
  9. Daphney OgolaBehavior Technician1255906202
  10. Jamie Oh, LVNLicensed Vocational Nurse1679196091
  11. Diana OjedaClinical Social Worker1083156129
  12. Jaqueline OjedaCase Manager/Care Coordinator1750038055
  13. Diana Ojeda-RoblesBehavior Technician1104499813
  14. Adora Okam, DDSGeneral Practice Dentistry1679657159
  15. Lee Okelue, AMFT/APCCStudent in an Organized Health Care Education/Training Program1073459400
  16. Ndidi OkwaleSocial Worker1861877615
  17. Elizabeth OlajideProsthetist1134752942
  18. Megan Oleary, RNRegistered Nurse1194245597
  19. Denise OlivaCase Manager/Care Coordinator1053865170
  20. Kimberly OlivaBehavior Technician1811456304
  21. Karina OlivaresBehavior Technician1609678820
  22. Rosario OlivaresAssistant Behavior Analyst1013788124
  23. Brian Olivas, AMFT #147572Marriage & Family Therapist1124767538
  24. Stephanie OlivasRehabilitation Practitioner1699096578
  25. Andrea Oliveau, D.C.Chiropractor1649339904
  26. Vanessa OliverBehavior Technician1194357483
  27. Erica Olmos, RNGeneral Practice Registered Nurse1962375030
  28. Vanessa OlmosDental Assistant1457947293
  29. Debra Olson, DCChiropractor1710194980
  30. Vanessa Olton, MDFamily Medicine Physician1811375702
  31. Samantha OlujichLicensed Vocational Nurse1831937432
  32. Wale Olukanmi, PA-CMedical Physician Assistant1538386495
  33. Angelique OlveraBehavior Technician1265163968
  34. Stella Ondieki, FNPFamily Nurse Practitioner1659810406
  35. Uchenna Onuekwusi, RNPsychiatric/Mental Health Registered Nurse1417766619
  36. Katelyn OnyekweluBehavior Technician1326988601
  37. Shwe Yee Oo, M.D.Family Medicine Physician1306280789
  38. Tun OoInternal Medicine Physician1477973865
  39. Ira Opatowsky, MDSpecialist1659374445
  40. Bert OpleAmbulatory Care Registered Nurse1851003362
  41. Latrice OrantesClinical Social Worker1902264047
  42. Vanessa OrdasCase Manager/Care Coordinator1669125175
  43. Ruth Oren, M.D.Anesthesiology Physician1821123696
  44. Erica Orenos-GarciaStudent in an Organized Health Care Education/Training Program1326735416
  45. Amanda OrmondeMarriage & Family Therapist1245016732
  46. Veronica OrnelasBehavior Technician1962102772
  47. Franciscca OrozcoPeer Specialist1386492510
  48. Jessica OrozcoCommunity Health Worker1114746542
  49. Martin Orro, DDSGeneral Practice Dentistry1982795837
  50. Alexa OrtegaDay Training/Habilitation Specialist1982586251

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

Lancaster, California appears in the CMS National Plan and Provider Enumeration System with 4,273 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 Lancaster - 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 Lancaster 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 Lancaster is weighted toward Behavior Technician (436 clinicians, followed by Marriage & Family Therapist with 331 and Addiction (Substance Use Disorder) Counselor with 283). 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, Lancaster reports roughly 11 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 Lancaster 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 Lancaster, CA?

There are 4,273 registered healthcare providers in Lancaster, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.

What are the most common medical specialties in Lancaster?

The most common specialties in Lancaster are Behavior Technician, Marriage & Family Therapist, Addiction (Substance Use Disorder) Counselor, Case Manager/Care Coordinator, Clinical Social Worker. Behavior Technician has the most providers with 436.

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.