Doctors and health care providers in Castro Valley, CA
999 individual NPPES records list a practice address in Castro Valley, 189th of 812 California cities. The largest group is behavior technician: 72, 7% of the city's records, against 18% across California. Page 20 of 20.
The 8 largest groups in Castro Valley
Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.
Castro Valley in California
- Rank in California189th of 812 cities by records
- Share of the state0.1% of California's records
- Specialties present25 or more taxonomy codes
- Top three groups18.8% of all records
Compared with California as a whole, Castro Valley has 9.1× the state's share of hospitalist physician records and 0.41× its share of behavior technician records.
Providers in Castro Valley, alphabetically
- Julian WilliamsBehavior Analyst1043017825
- Teaira WilliamsCommunity Health Worker1770323321
- Ann Wilson, PSY.D.Clinical Psychologist1528312725
- Byron Wilson, M.D.Medical Oncology Physician1992736367
- Ellen Wilson, PT, DPTPhysical Therapist1174284517
- Isabelle WilsonPsychiatric/Mental Health Registered Nurse1598506263
- James Wilson, DDSGeneral Practice Dentistry1598754673
- Zane Wilson, NPAcute Care Nurse Practitioner1801656228
- Daniel Wittman, D.C.Chiropractor1720177009
- David WohlnerHealth Educator1356152540
- John Wong, O.D.Optometrist1457371619
- Lawrence Wong, DMDGeneral Practice Dentistry1043879653
- Michelle Wong, PA-CPhysician Assistant1932201977
- Terence Wong, D.D.S.General Practice Dentistry1326176462
- Sandi Woo, PA-CMedical Physician Assistant1225103161
- William Wood, M.D., M.S.Surgery Physician1821309022
- Bryan Worthy, D.C.Chiropractor1356422810
- L. Wu, O.D.Optometrist1770523763
- Annika WurmStudent in an Organized Health Care Education/Training Program1093507469
- Kun Xiao, MD MPHHematology & Oncology Physician1710326889
- Ling Xu, M.D.Internal Medicine Physician1073684429
- Weiwei Xu, MDUrology Physician1992837702
- Helen Yang, MDInternal Medicine Physician1003270877
- Jiaqi Yang, R.D.Registered Dietitian1750784567
- Shervin Yazdi, D.D.S.Pediatric Dentistry1376697524
- Ruiyu YePharmacist1790237022
- Yuwei YePhysical Therapist1447137674
- Craig Yeager, RNPsychiatric/Mental Health Registered Nurse1316810989
- Alana Yee, OTR/LOccupational Therapist1194410662
- Amanda Yee, MDObstetrics & Gynecology Physician1497316608
- Janice Young, RDHAPDental Hygienist1265378913
- Jennifer Young, D.D.S.Dentist1215071113
- Samantha Young, ODOptometrist1982259628
- Jennifer YuMental Health Counselor1144922832
- Zhao YuBehavior Technician1679454862
- Matthew Yuen, DDSDentist1568010882
- Richard ZamoraAddiction (Substance Use Disorder) Counselor1215807136
- Jeffrey ZellnerSpecialist1104020478
- Mark Zeme, M. D.Otolaryngology Physician1669400388
- Xi Zhai, DOFamily Medicine Physician1083148050
- Boris Zhalkovsky, MDPsychiatry Physician1518146489
- Qiliang Zhang, D.O.Anesthesiology Physician1275830234
- Rose Zhang, NPRegistered Nurse1609268382
- Yifan ZhangFamily Nurse Practitioner1841953874
- Geena Zhou, MDPediatrics Physician1629659206
- Xiaoning Zhou, MDAnesthesiology Physician1467403394
- Tian Hao ZhuDermatology Physician1033640537
- Gary Zoffada, DCChiropractor1073675963
- Steven Zourabian, D.O.Orthopaedic Trauma Physician1578918926
The largest California cities
- Los Angeles69,537
- San Diego52,937
- San Francisco38,143
- Sacramento33,083
- San Jose20,925
How to read this directory
Castro Valley, California appears in the CMS National Plan and Provider Enumeration System with 999 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 Castro Valley - 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 Castro Valley 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 Castro Valley is weighted toward Behavior Technician (72 clinicians, followed by Marriage & Family Therapist with 68 and Pharmacist with 48). 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, Castro Valley reports roughly 2.6 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 Castro Valley practice address, a coverage gap Castro Valley patients typically fill by traveling to a larger nearby hub.
For Castro Valley 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 Castro Valley, CA?
There are 999 registered healthcare providers in Castro Valley, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.
What are the most common medical specialties in Castro Valley?
The most common specialties in Castro Valley are Behavior Technician, Marriage & Family Therapist, Pharmacist, Physical Therapist, Chiropractor. Behavior Technician has the most providers with 72.
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.