Internal Medicine Physician in Fontana, CA
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-20.
112 providers
The CMS National Plan and Provider Enumeration System currently lists 112 Internal Medicine Physician providers with a primary practice address in Fontana, CA, all registered under the Internal Medicine NUCC taxonomy branch. Each clinician on this roster selected Internal Medicine Physician as their primary taxonomy at NPI enrollment, a self-reported classification updated whenever the provider files a correction with CMS. Every figure is drawn from the federal National Provider Identifier Registry (CMS NPPES); see our methodology.
Before contacting anyone on this list, verify the practice is still at the address shown. NPPES refreshes monthly, but providers who have relocated, retired, or changed employers may not have filed an NPI update yet. Important: PlainDoctor is a directory of publicly available CMS government data, not a quality ranking, a board-certification verifier, or medical advice. Always confirm credentials through the NPPES NPI Registry before making any clinical decision.
Showing the first 50 of 112 providers. Browse the full Internal Medicine Physician directory for CA.
Provider data from CMS NPPES (download.cms.gov/nppes). Specialty classification from NUCC Health Care Provider Taxonomy (nucc.org). PlainDoctor does not rate or rank providers. Methodology · About