Ltrl Health Data

Methodology

How Ltrl Health Data counts healthcare providers and where every number comes from.

Counting rules

  • Individual clinicians only (NPI type 1), counted once, under their primary taxonomy (the primary flag; otherwise the lowest listed code).
  • Placed at their practice-location county, using the HUD ZIP-to-county crosswalk (the county with most business addresses for the ZIP).
  • Active means not deactivated, or reactivated on or after the deactivation date.
  • Rates are count ÷ Census population × 100,000; ratios are residents per provider. State and US figures are pooled (total providers ÷ total population).
  • Counts under 10, or places with fewer than 10,000 residents, carry a small-number flag and are not ranked. A count of 0 is shown as 0.
  • Nothing is estimated, modelled or imputed. Insurance and preventive-care measures are published values from Census SAHIE and CMS Mapping Medicare Disparities, ingested as published.
  • History: June NPPES snapshots for 2021–2025 (archived by NBER) and the latest monthly registry data, counted with the same definitions.
  • Medicare-enrolled share: of a measure's providers in a place, the share also listed in the newest CMS Doctors & Clinicians release (at any practice location). Both are direct counts; the share is shown only for the latest monthly data, never back-filled to earlier years.
  • Benchmark: beside our primary care physician and dentist counts, county pages show the HRSA Area Health Resources File (AHRF) value as published, with its data year. AHRF counts physicians from AMA records (non-federal, patient care, residents excluded) and dentists from NPPES, so it is a cited comparison, not part of our count.

Registered, not necessarily practicing. The registry lists clinicians who hold an NPI; some are retired or see few patients, so counts can exceed the number actively seeing patients.

Measures and code lists

Dentists

Active individual NPIs whose primary taxonomy is a dentist (general or specialist; NUCC 1223 and Oral Medicine). Shares its definition with the dentists specialty group.

NUCC codes (14): 122300000X, 1223D0001X, 1223D0004X, 1223E0200X, 1223G0001X, 1223P0106X, 1223P0221X, 1223P0300X, 1223P0700X, 1223S0112X, 1223X0008X, 1223X0400X, 1223X2210X, 125Q00000X

Counted from the federal NPI registry (CMS NPPES): active individual providers, by primary taxonomy and primary practice location.

Mental health providers

Active individual NPIs whose primary taxonomy is a psychiatrist, an addiction-medicine physician, a psychologist or clinical neuropsychologist, a clinical social worker, a counselor (general, mental health, professional, addiction), a marriage & family therapist, or a psychiatric/mental-health nurse practitioner or clinical nurse specialist. School and pastoral counselors are not included. Reported as providers per 100,000 residents and as residents per provider.

NUCC codes (49): 101Y00000X, 101YA0400X, 101YM0800X, 101YP2500X, 103G00000X, 103GC0700X, 103T00000X, 103TA0400X, 103TA0700X, 103TB0200X, 103TC0700X, 103TC1900X, 103TC2200X, 103TE1000X, 103TE1100X, 103TF0000X, 103TF0200X, 103TH0004X, 103TH0100X, 103TM1700X, 103TM1800X, 103TP0016X, 103TP0814X, 103TP2700X, 103TP2701X, 103TR0400X, 103TS0200X, 103TW0100X, 1041C0700X, 106H00000X, 207LA0401X, 207QA0401X, 207RA0401X, 2083A0300X, 2084A0401X, 2084F0202X, 2084P0015X, 2084P0800X, 2084P0802X, 2084P0804X, 2084P0805X, 363LP0808X, 364SP0807X, 364SP0808X, 364SP0809X, 364SP0810X, 364SP0811X, 364SP0812X, 364SP0813X

Counted from the federal NPI registry (CMS NPPES): active individual providers, by primary taxonomy and primary practice location.

Other primary care providers

Active individual NPIs whose primary taxonomy is a nurse practitioner in a primary-care field (general, family, adult health, pediatrics, gerontology or primary care) or a general physician assistant. Women's-health, school, community-health, acute-care, critical-care, neonatal, psychiatric and OB-GYN NPs, and medical and surgical PAs, are not included.

NUCC codes (7): 363A00000X, 363L00000X, 363LA2200X, 363LF0000X, 363LG0600X, 363LP0200X, 363LP2300X

Counted from the federal NPI registry (CMS NPPES): active individual providers, by primary taxonomy and primary practice location.

Primary care physicians

Active individual NPIs whose primary taxonomy is general Family Medicine (incl. Adult Medicine, Geriatric Medicine), general Internal Medicine (incl. Geriatric Medicine), general Pediatrics or General Practice. Shares its definition with the primary-care specialty group. NPPES registration counts run above AMA-based practicing-physician counts; the methodology page shows AHRF as a benchmark.

NUCC codes (7): 207Q00000X, 207QA0505X, 207QG0300X, 207R00000X, 207RG0300X, 208000000X, 208D00000X

Counted from the federal NPI registry (CMS NPPES): active individual providers, by primary taxonomy and primary practice location.

Flu vaccinations

Percent of fee-for-service Medicare enrollees with a reimbursed influenza vaccination during the year, age-standardized, as published by CMS MMD.

CMS Office of Minority Health, Mapping Medicare Disparities Tool.

Mammography screening

Percent of fee-for-service Medicare enrollees in MMD's screening-mammography population who received a screening mammogram, unadjusted, as published by CMS MMD.

CMS Office of Minority Health, Mapping Medicare Disparities Tool.

Preventable hospital stays

Hospital stays for ambulatory-care–sensitive conditions (AHRQ Prevention Quality Overall Composite, PQI 90) per 100,000 fee-for-service Medicare enrollees, age-standardized, as published by CMS MMD.

CMS Office of Minority Health, Mapping Medicare Disparities Tool.

Uninsured (under 65)

Percent of people under 65 without health insurance, as published by Census SAHIE (90% margin of error shown).

U.S. Census Bureau, Small Area Health Insurance Estimates (SAHIE).

Uninsured adults (18–64)

Percent of adults 18–64 without health insurance, as published by Census SAHIE.

U.S. Census Bureau, Small Area Health Insurance Estimates (SAHIE).

Uninsured children (under 19)

Percent of children under 19 without health insurance, as published by Census SAHIE.

U.S. Census Bureau, Small Area Health Insurance Estimates (SAHIE).

Medicare-enrolled share

Of a provider measure's providers in an area, the share also listed in the latest CMS Doctors & Clinicians release (enrolled in Medicare). Both counts are direct counts.

Counted from CMS NPPES and CMS Doctors & Clinicians.

How our numbers compare

MeasureReleaseLevelComparedr (log rates)Within ±10%Median ratio
Dentists2025county2,9080.9888%1.00
Dentists2025national1—100%1.01
Dentists2025state511.00100%1.00
Dentists2024county2,9030.9779%1.00
Dentists2024national1—100%0.99
Dentists2024state511.00100%0.98
Mental health providers2025county2,9590.9985%1.02
Mental health providers2025national1—100%1.04
Mental health providers2025state511.00100%1.04
Mental health providers2024county2,9300.9986%1.02
Mental health providers2024national1—100%1.04
Mental health providers2024state511.0098%1.04
Mental health providers2023county2,9130.9987%1.01
Mental health providers2023national1—100%1.04
Mental health providers2023state511.00100%1.03
Mental health providers2022county2,9000.9988%1.00
Mental health providers2022national1—100%1.03
Mental health providers2022state511.0098%1.03
Other primary care providers2025county3,0770.9561%1.03
Other primary care providers2025national1—100%1.07
Other primary care providers2025state510.9676%1.05
Other primary care providers2024county3,0670.9561%1.02
Other primary care providers2024national1—100%1.06
Other primary care providers2024state510.9680%1.04
Other primary care providers2023county3,0630.9563%1.00
Other primary care providers2023national1—100%1.05
Other primary care providers2023state510.9686%1.03
Other primary care providers2022county3,0550.9461%1.00
Other primary care providers2022national1—100%1.04
Other primary care providers2022state510.9686%1.02
Primary care physicians2025county2,9780.7313%1.46
Primary care physicians2025national1—0%1.46
Primary care physicians2025state510.890%1.41

Compared with County Health Rankings & Roadmaps' published values (University of Wisconsin Population Health Institute, via Zenodo, CC BY 4.0). Aggregate statistics only; we never republish their values. Ltrl is not affiliated with County Health Rankings & Roadmaps.