NPPES file of Aug 9, 2026

Doctors and health care providers in Walnut Creek, CA

6,170 individual NPPES records list a practice address in Walnut Creek, 23rd of 812 California cities. The largest group is behavior technician: 1,764, 29% of the city's records, against 18% across California. Page 82 of 124.

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

The 8 largest groups in Walnut Creek

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

Walnut Creek in California

  • Rank in California23rd of 812 cities by records
  • Share of the state0.6% of California's records
  • Specialties present25 or more taxonomy codes
  • Top three groups37.6% of all records

Compared with California as a whole, Walnut Creek has 3.5× the state's share of hospitalist physician records and 0.39× its share of mental health counselor records.

Providers in Walnut Creek, alphabetically

  1. Tighe Ohanrahan, MDFamily Medicine Physician1316977846
  2. Keiko OhashiPharmacist1568893741
  3. Grace OhwobeteBehavior Technician1053289918
  4. Joanne OhwobeteBehavior Technician1265396550
  5. Madison OilerBehavior Technician1578120515
  6. Kimberly Oja, NPAdult Health Nurse Practitioner1396245064
  7. Anahi OjedaBehavior Technician1861042103
  8. Tessie Okamura, M.D.Pediatrics Physician1063446102
  9. Naomi Okawa, RN,IBCLCLactation Consultant (Registered Nurse)1043808850
  10. Mark Okawachi, PA-CSurgical Physician Assistant1114078631
  11. Chetachi Okereke, M.D, M.B.B.SRheumatology Physician1083842199
  12. Hector Oksenendler, DCPhysical Therapist1922101435
  13. Angela OliphantBehavior Technician1740148204
  14. Maria Teresa OlivaMarriage & Family Therapist1750685970
  15. Grace OlivasBehavior Technician1013807601
  16. Chelsea OliverBehavior Technician1821638529
  17. Rachel OliverFamily Medicine Physician1861845554
  18. Griselda Oliver Bucio, LMFTMarriage & Family Therapist1467918821
  19. Rhoda Olkin, PH.D.Specialist1366509838
  20. Joshua OllivierBehavior Technician1922787860
  21. Laura Olmstead, RPHPharmacist1811301088
  22. Steven Olsen, MDFamily Medicine Physician1457434128
  23. Jeffrey Olson, CPHTOther Technician1114358678
  24. Jacqueline Olympius, PA-CPhysician Assistant1578273579
  25. Emily OmaqueAssistant Behavior Analyst1184120180
  26. Denise Omen, RPHPharmacist1598838773
  27. Long On, PSY.D.Clinical Psychologist1053627117
  28. Julia Ondarza, PA-CPhysician Assistant1013537794
  29. Kelsey OneilClinical Social Worker1508582677
  30. Arlene OngpinRenal Dialysis Technician1578306098
  31. Lori Ono, PH.D.Clinical Psychologist1487719928
  32. Chioma OnyeaguchaBehavior Technician1720657745
  33. Bethany OnyweraBehavior Technician1902380389
  34. Samuel Oommen, M.D.Surgery Physician1942385851
  35. Marianna Oppenheimer, MD, MSCEmergency Medicine Physician1538657762
  36. Mona Orady, M.D.Obstetrics & Gynecology Physician1003970773
  37. Roy Orden, MDAllergy Physician1861781056
  38. Emily OrellanaBehavior Technician1053883736
  39. Esmeralda Orellana, M.EDAssistant Behavior Analyst1972467181
  40. Jon Christopher Orlino, M.D.Vascular Surgery Physician1265963789
  41. Linda Ormonde, P.T.Physical Therapist1356402655
  42. Zyna OrongBehavior Technician1215663588
  43. Ivy OronosBehavior Technician1437621513
  44. Jodi Oronsky, PTPhysical Therapist1467614883
  45. Sophia OropezaBehavior Analyst1417840950
  46. Alondra OrozcoBehavior Technician1174381727
  47. Elena OrozcoBehavior Technician1215796206
  48. Yadira OrozcoBehavior Technician1376206052
  49. Sandra Orozco Loza, LCSWClinical Social Worker1104116250
  50. Chelsea OrquizBehavior Analyst1336685213

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

Walnut Creek, California appears in the CMS National Plan and Provider Enumeration System with 6,170 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 Walnut Creek - 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 Walnut Creek 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 Walnut Creek is weighted toward Behavior Technician (1,764 clinicians, followed by Marriage & Family Therapist with 315 and Pharmacist with 239). 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, Walnut Creek reports roughly 15.8 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, Student in an Organized Health Care Education/Training Program is the most prominent one with no provider currently listing a Walnut Creek practice address, a coverage gap Walnut Creek patients typically fill by traveling to a larger nearby hub.

For Walnut Creek 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 Walnut Creek, CA?

There are 6,170 registered healthcare providers in Walnut Creek, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.

What are the most common medical specialties in Walnut Creek?

The most common specialties in Walnut Creek are Behavior Technician, Marriage & Family Therapist, Pharmacist, Behavior Analyst, Internal Medicine Physician. Behavior Technician has the most providers with 1,764.

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.