NPPES file of Aug 9, 2026

Doctors and health care providers in Diamond Bar, CA

598 individual NPPES records list a practice address in Diamond Bar, 261st of 812 California cities. The largest group is speech-language pathologist: 45, 8% of the city's records, against 1% across California. Page 9 of 12.

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).

The 8 largest groups in Diamond Bar

  1. Speech-Language Pathologist45
  2. Pharmacist42
  3. General Practice Dentistry39
  4. Physical Therapist37
  5. Acupuncturist35
  6. Marriage & Family Therapist30
  7. Dentist26
  8. Family Medicine Physician25

Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.

Diamond Bar in California

  • Rank in California261st of 812 cities by records
  • Share of the state<0.1% of California's records
  • Specialties present25 or more taxonomy codes
  • Top three groups21.1% of all records

Compared with California as a whole, Diamond Bar has 5.6× the state's share of speech-language pathologist records and 0.10× its share of behavior technician records.

Providers in Diamond Bar, alphabetically

  1. Nikolas Nemeth, NPFamily Nurse Practitioner1538869946
  2. Shui Sha NgInterpreter1285431825
  3. Elizabeth NgoStudent in an Organized Health Care Education/Training Program1245111616
  4. Francine NguyenPhysical Therapist1912774548
  5. Krystal NguyenStudent in an Organized Health Care Education/Training Program1215873393
  6. Nhu Nguyen, M.D.Child & Adolescent Psychiatry Physician1497067185
  7. Samantha Nguyen, MS,AMFTMarriage & Family Therapist1003321050
  8. Susan NguyenPharmacist1316224090
  9. Tiffany Nguyen, MD, MSPediatrics Physician1356083927
  10. Elaine Nhan, DPTOrthopedic Physical Therapist1164207809
  11. April NicholsBehavior Analyst1912412149
  12. Jack Oh, D.D.S.General Practice Dentistry1609844505
  13. Graciela Olid, MSMarriage & Family Therapist1609918846
  14. Christina OliveraMarriage & Family Therapist1972736775
  15. Andriani Ongkorahardjo, DDSPediatric Dentistry1902941669
  16. Richard Ortigo, PSYDClinical Psychologist1154551158
  17. Jonathan Ou, M.DInternal Medicine Physician1518109719
  18. Kathy Ou, PHARM.DPharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1366887416
  19. Stephen Ou, MDStudent in an Organized Health Care Education/Training Program1669763439
  20. Jongson Pak, DDS GENERAL DENTISTRDentist1982861894
  21. Jieru Pan, DDSGeneral Practice Dentistry1184823957
  22. Yann Ping Pan, MDFamily Medicine Physician1114250925
  23. Parvita Panchal, DOFamily Medicine Physician1730683145
  24. Lucas Paredes, D.CChiropractor1215490263
  25. Angela ParkMarriage & Family Therapist1104447341
  26. Grace Park, D.C.Chiropractor1679970859
  27. Hee Park, ACUPUNCTURISTAcupuncturist1053433235
  28. John Park, PHDClinical Psychologist1750632501
  29. Jong Park, LAC.Acupuncturist1760749352
  30. Ritchie Park, D.D.S.General Practice Dentistry1033248174
  31. Shin ParkAcupuncturist1306333216
  32. Ashley Marie Pascua, PTAPhysical Therapy Assistant1275410961
  33. Dilipkumar Patel, DDSGeneral Practice Dentistry1154315265
  34. Rajul Patel, DDSDentist1457576423
  35. Romi Patel, DDSDentist1144791377
  36. Shagufta Patel, DPTPhysical Therapist1427934876
  37. Sonal Pathak, MS, CCC-SLPSpeech-Language Pathologist1184990822
  38. Jonathan Patuwo, DDSGeneral Practice Dentistry1699259713
  39. Chase Paulson, MS, ATCAthletic Trainer1467751552
  40. Oscar Perez, LCSWClinical Social Worker1689811911
  41. Nancy Pham, PHARMDPharmacist1265900377
  42. Warren PhanPhysical Therapist1912830704
  43. Rhea PhilipSpeech-Language Pathologist1063343119
  44. David Picella, PHD, FNP, GS-C, CPGFamily Nurse Practitioner1548426380
  45. Dominic Pisigan, NP-CFamily Health Clinical Nurse Specialist1285058727
  46. Nathan Pliam, MD, PH.D.Orthopaedic Surgery Physician1710040944
  47. Bertha PonceSpeech-Language Assistant1578406385
  48. Jane PoonClinical Social Worker1386049609
  49. Dhanashree PotdarOccupational Therapist1750819835
  50. Neeta Prakash, SPEECH LANGUAGE PATHSpeech-Language Pathologist1568025161

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

Diamond Bar, California appears in the CMS National Plan and Provider Enumeration System with 598 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 Diamond Bar - 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 Diamond Bar 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 Diamond Bar is weighted toward Speech-Language Pathologist (45 clinicians, followed by Pharmacist with 42 and General Practice Dentistry with 39). 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, Diamond Bar reports roughly 1.5 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.

Of California's most common specialties, Addiction (Substance Use Disorder) Counselor is the most prominent one with no provider currently listing a Diamond Bar practice address, a coverage gap Diamond Bar patients typically fill by traveling to a larger nearby hub.

For Diamond Bar 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 Diamond Bar, CA?

There are 598 registered healthcare providers in Diamond Bar, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.

What are the most common medical specialties in Diamond Bar?

The most common specialties in Diamond Bar are Speech-Language Pathologist, Pharmacist, General Practice Dentistry, Physical Therapist, Acupuncturist. Speech-Language Pathologist has the most providers with 45.

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.