{"license":"https://creativecommons.org/licenses/by/4.0/","dataset":"geography","system":"insurance","systemMatched":true,"requestedSystem":"insurance","availableSystems":["insurance","banking"],"availableHistoricalSystems":["banking"],"marketKey":"us-individual-health-insurance","marketLabel":"U.S. individual health insurance","scopeKey":"us-individual-health-insurance","scopeLabel":"U.S. individual health insurance","metricLabel":"Market HHI","metricUnit":"HHI (0–10,000)","year":2024,"national":{"hhi":3650,"largestInsurerSharePct":48,"insurersOver5pct":4},"source":{"id":"kff-individual-insurance-market-2024","title":"Individual Insurance Market Competition (HHI by state)","publisher":"KFF","url":"https://www.kff.org/state-health-policy-data/state-indicator/individual-insurance-market-competition/","accessDate":"2026-06-23","methodologyNote":"KFF analysis of Medical Loss Ratio (MLR) Part 1 data from the Health Coverage Portal maintained by Mark Farrah Associates. HHI is the source-reported state-level value for the ACA-regulated individual market; firm-level shares are not re-derived here.","dataStatus":"estimated_public","confidenceLevel":"high"},"guardrail":"This geography layer describes the ACA-regulated individual health insurance market using KFF's 2024 state-level measures. It does not measure a state's overall economy, employer-sponsored insurance, or a legal market definition.","count":1,"filters":{"state":"CA","stateMatched":true,"stateCode":"CA","stateName":"California"},"rows":[{"system":"insurance","marketKey":"us-individual-health-insurance","marketLabel":"U.S. individual health insurance","metricLabel":"Market HHI","metricUnit":"HHI (0–10,000)","year":2024,"stateCode":"CA","stateName":"California","hhi":2389,"largestInsurerSharePct":33,"insurersOver5pct":5,"concentrationClass":"moderately_concentrated","sourceId":"kff-individual-insurance-market-2024","sourceTitle":"Individual Insurance Market Competition (HHI by state)","sourcePublisher":"KFF","sourceUrl":"https://www.kff.org/state-health-policy-data/state-indicator/individual-insurance-market-competition/","sourceProfileHref":"/sources/kff-individual-insurance-market-2024","accessDate":"2026-06-23","dataStatus":"estimated_public","confidenceLevel":"high","methodologyNote":"KFF analysis of Medical Loss Ratio (MLR) Part 1 data from the Health Coverage Portal maintained by Mark Farrah Associates. HHI is the source-reported state-level value for the ACA-regulated individual market; firm-level shares are not re-derived here.","guardrail":"This geography layer describes the ACA-regulated individual health insurance market using KFF's 2024 state-level measures. It does not measure a state's overall economy, employer-sponsored insurance, or a legal market definition."}]}