Doctors and health care providers in Rancho Cucamonga, CA
4,579 individual NPPES records list a practice address in Rancho Cucamonga, 41st of 812 California cities. The largest group is behavior technician: 1,830, 40% of the city's records, against 18% across California. Page 32 of 92.
The 8 largest groups in Rancho Cucamonga
Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.
Rancho Cucamonga in California
- Rank in California41st of 812 cities by records
- Share of the state0.5% of California's records
- Specialties present25 or more taxonomy codes
- Top three groups53.4% of all records
Compared with California as a whole, Rancho Cucamonga has 3.8× the state's share of behavior analyst records and 0.15× its share of student in an organized health care education/training program records.
Providers in Rancho Cucamonga, alphabetically
- Gina Gregory, LCSWClinical Social Worker1770795221
- Jennifer GretzCounselor1578716007
- Lucy Grey, NPFamily Nurse Practitioner1912254210
- Lori GreydanusAdult Health Nurse Practitioner1467247155
- Alex GriceBehavior Analyst1821812843
- Laci GriffinBehavior Technician1891421996
- Jack Griffith, DODermatology Physician1407884315
- Mercedes GrigollaAssistant Behavior Analyst1376311225
- Zachary GrimesBehavior Technician1699567800
- Danelle GuadamuzStudent in an Organized Health Care Education/Training Program1598185902
- Gabriela GuadianBehavior Technician1740176130
- Jessica Guarte, NPFamily Nurse Practitioner1427753870
- Amy GudielBehavior Technician1932852001
- Katelyn GuerenaBehavior Technician1508438342
- Angelica GuerraBehavior Technician1679226005
- Maricruz GuerraBehavior Technician1790672921
- Olga Guerra, MA CCC-SLPSpeech-Language Pathologist1972786853
- Alex GuerreroBehavior Technician1548938939
- Athenia Guerrero, O.T.Occupational Therapist1295954279
- Bertha GuerreroPharmacy Technician1437725132
- Haleigh GuerreroBehavior Analyst1912853383
- Laura Guerrero, NPFamily Nurse Practitioner1831292184
- Lauren GuerreroBehavior Technician1780573519
- Shizatiz Guerrero, LCSWClinical Social Worker1861938557
- Juanita Guevara, LCSWClinical Social Worker1316218266
- Angie Guijose, RBTBehavior Technician1962210484
- Taja Gullens, RBTBehavior Technician1619837168
- Lori Gumescheimer, 224Z00000XOccupational Therapy Assistant1679452122
- Edward Gundrum, D.O.Anesthesiology Physician1013119734
- Timothy Gunn, PSY.D.Psychologist1356466973
- Michael Gunther, DPTPhysical Therapist1184016644
- Sandra GustafsonBehavior Analyst1306775663
- Aileen GutierrezBehavior Technician1558179044
- Andre GutierrezBehavior Technician1245154137
- Diana GutierrezBehavior Technician1700637055
- Evangelina Gutierrez, BEHAVIORISTBehavior Technician1245102441
- Isabella GutierrezBehavior Technician1194484220
- Jessenia GutierrezBehavior Analyst1861325391
- Kimberly GutierrezBehavior Technician1689560195
- Kitzia GutierrezBehavior Technician1316627268
- Laura GutierrezSocial Worker1144800822
- Mallory GutierrezBehavior Technician1205750866
- Rick Gutierrez, BCBABehavior Analyst1689974917
- Roxanna GutierrezBehavior Technician1558253252
- Tara GutierrezBehavior Technician1811867062
- Vivianna GutierrezBehavior Technician1508720996
- Yessenia GutierrezBehavior Technician1306586599
- Samantha Gutierrez-CurranSpeech-Language Assistant1851907679
- Jessica Gutierrez-RomeroClinical Social Worker1033698931
- Amanda Guzallis, AUDAudiologist1174017560
The largest California cities
- Los Angeles69,537
- San Diego52,937
- San Francisco38,143
- Sacramento33,083
- San Jose20,925
How to read this directory
Rancho Cucamonga, California appears in the CMS National Plan and Provider Enumeration System with 4,579 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 Rancho Cucamonga - 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 Rancho Cucamonga 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 Rancho Cucamonga is weighted toward Behavior Technician (1,830 clinicians, followed by Behavior Analyst with 367 and Marriage & Family Therapist with 248). 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, Rancho Cucamonga reports roughly 11.8 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, Addiction (Substance Use Disorder) Counselor is the most prominent one with no provider currently listing a Rancho Cucamonga practice address, a coverage gap Rancho Cucamonga patients typically fill by traveling to a larger nearby hub.
For Rancho Cucamonga 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 Rancho Cucamonga, CA?
There are 4,579 registered healthcare providers in Rancho Cucamonga, CA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.
What are the most common medical specialties in Rancho Cucamonga?
The most common specialties in Rancho Cucamonga are Behavior Technician, Behavior Analyst, Marriage & Family Therapist, Pharmacist, Clinical Social Worker. Behavior Technician has the most providers with 1,830.
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.