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Research/Tools/Access-gap lookup
FREE TOOL · NO SIGNUP

Provider Access Gap Lookup

Type a state or ZIP plus a medical specialty. Get the per-100,000 provider density figure with national percentile, three comparable states, and a citeable result block. CMS NPPES + U.S. Census, fully sourced. Free.

Try a high-volume example

Pre-rendered county pages for the eight most-populous U.S. counties × Dermatologists:

  • Los Angeles County, CA
  • Cook County, IL
  • Harris County, TX
  • Maricopa County, AZ
  • San Diego County, CA
  • Orange County, CA
  • Miami-Dade County, FL
  • Dallas County, TX

How it works

  1. For each specialty, Fonteum runs a daily snapshot of the public CMS NPPES NPI Registry, filtering to the relevant taxonomy codes.
  2. State counts are divided by U.S. Census Bureau 2024-vintage population estimates to get density per 100,000 residents.
  3. Each state is ranked by density. The percentile shown is the queried state's position within the 51-jurisdiction ranking (50 states + DC).
  4. For ZIP and county queries, the result surfaces state-level density with the geographic context preserved — NPPES doesn't publish a county-level field of practice in its public API.

Full methodology →

Specialties covered

  • Dermatologists
  • Psychiatrists
  • Cardiologists
  • OB-GYNs
  • Pediatricians
  • Neurologists
  • Oncologists
  • Orthopedic surgeons
  • Ophthalmologists
  • Gastroenterologists
  • Urologists
  • Otolaryngologists (ENT)
  • Chiropractors
  • Plastic surgeons

Each specialty links to its parent Fonteum Research study with the full per-state dataset, methodology, and Limitations.

Source & limitations

Source: U.S. Centers for Medicare & Medicaid Services NPI Registry (NPPES) public API + U.S. Census Bureau Population Estimates Program (PEP), 2024 vintage. Snapshot date is published on every result page.

This tool measures density, not access. Drive time, appointment availability, insurance acceptance, and wait times are not modeled. The full Limitations doctrine is repeated on every result page.

Free to cite with attribution to Fonteum Research and a link to this tool.

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Reviewed by Jennifer Montecillo, MD, medical reviewer. Non-practicing medical reviewer.

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