Provider Concentration

Provider Concentration — Where Is Access Fragile?

Market concentration matters because it determines resilience. When many providers serve a category, one leaving is a minor event. When two or three providers dominate, one leaving is a crisis. This page measures how concentrated Medicaid service delivery is — and where it's dangerously thin.

Provenance

Methodological Guardrails

Market Concentration by Service Category

The HHI (Herfindahl-Hirschman Index) measures how evenly spending is distributed across providers. Higher = more concentrated. The DOJ considers markets above 2,500 "highly concentrated." At the broad national category level, no Medicaid market hits that threshold — but that can mask extreme local concentration.

SELECT * FROM medicaid.concentration_by_category

Citation: concentration (source medicaid.concentration_by_category).

Home Health has the highest HHI (44) and the highest single-provider share (~4%). This makes sense — home health is dominated by large fiscal intermediaries and managed care organizations that bill on behalf of thousands of individual aides. The top provider in this category billed over 5 billion dollars across the dataset.

E&M / Office Visits and Dental are the most competitive, with low HHI and 280K+ and 70K+ providers respectively. This is a healthy market structure — losing any single provider doesn't materially affect access.

Top 25 Providers

These are the 25 billing NPIs with the highest total Medicaid payments from January 2018 through October 2024.

SELECT * FROM medicaid.top_providers

Citation: providers (source medicaid.top_providers).

The City/State columns now reveal where these top spenders are based, and Type distinguishes individuals (1) from organizations (2). The top provider billed multiple billions over the analysis period. These aren't individual doctors — they're large organizations: managed care intermediaries, state agencies, hospital systems, and home health agencies that bill under a single NPI. The procedure_count column is revealing: providers with very few procedure codes (5-6) are typically fiscal intermediaries processing one type of service at massive scale. Providers with 50-100+ codes are more likely health systems delivering diverse care.

What This Means for Policy

Concentration analysis at the national level is a starting point, not a conclusion. The key policy questions require geographic drill-down:

• Network adequacy: Does every county have at least 2-3 providers for essential services? If one closes, can patients get care within a reasonable distance?
• Counter-party risk: If a state's largest home health agency exits Medicaid, how many beneficiaries are stranded?
• Anti-consolidation: Are provider mergers reducing the number of Medicaid participants in already-thin markets?

For state-level geographic breakdowns of spending, provider capacity, and ER reliance, see the Geographic Analysis page.

Reproduce This Page

cd dashboard
export EVIDENCE_SOURCE__medicaid__token="<your_motherduck_token>"
export EVIDENCE_SOURCE__medicaid__database="medicaid"
npm run sources
npm run build
npm run preview
# then open http://localhost:3000/concentration