Public dataset
Individual Insurance Market Competition (HHI by state)
KFF
- Rows
- 51
- Years
- 2024
- Accessed
- Jun 23, 2026
Canonical indicator / state-health-leader-share
State leading-insurer share
Largest insurer's share of the ACA-regulated individual market in each state.
Geographic screensPercentCalendar or release year2024
Snapshot median
47.0%Middle of 51 bounded observations- Observations
- 51
- 51 bounded entities
- Coverage
- 2024
- 1 observed period
- Sources
- 1
- KFF
- Exact pair
- r 0.959
- 51 entity-period matches
Indicator dossierState leader share51 observations / 2024
01 / Measurement contract
Definition before comparison
The unit, universe, period, and source boundary travel with every observation.
What this series measures
Largest insurer's share of the ACA-regulated individual market in each state.
State indicators describe the 2024 ACA-regulated individual health insurance market only. They do not measure a state's overall economy or employer-sponsored insurance.
- Indicator ID
- state-health-leader-share
- Unit
- Percent
- Observation dimension
- Jurisdiction
- Grouping field
- Census region
- Period basis
- Calendar or release year
- Ranking contract
- Use the latest available row for each entity
02 / Observed variation
Entity distribution and ranked anchors
2024; absent and withheld values do not enter the distribution.
- Minimum
- 23.0%
- 25th percentile
- 37.5%
- Median
- 47.0%
- 75th percentile
- 57.0%
- Maximum
- 81.0%
Selected interval28.8% to 34.6%8 observations / 15.7% of the snapshot
03 / Coverage and quality
Where the series has evidence
Observed rows are counted explicitly by period, group, verification status, and confidence level.
Period ledger1 observed period
202451 entities511 source
Evidence stateAll indicator observations
Data status
100.0%Estimated public / 51Confidence
100.0%High / 51Census regionLatest bounded snapshot, largest groups first
| Group | Rows | Average | Range |
|---|---|---|---|
| South | 17 | 51.1% | 38.0% to 81.0% |
| West | 13 | 46.3% | 26.0% to 74.0% |
| Midwest | 12 | 43.6% | 23.0% to 75.0% |
| Northeast | 9 | 52.1% | 30.0% to 73.0% |
04 / Exact paired lens
State HHI and leading-insurer share
State HHI and largest-insurer share for the same 2024 ACA individual market.
Same entity + same period0.959Pearson correlation across 51 exact pairs
-1 inverse 0 +1 aligned
- Pairing rule
- Same jurisdiction, market scope, and calendar year
- Companion indicator
- State HHI
- Matched current-series rows
- 51 / 51 (100.0%)
- Unpaired current-series rows
- 0; excluded from correlation
Interpretation boundaryState indicators describe the 2024 ACA-regulated individual health insurance market only. They do not measure a state's overall economy or employer-sponsored insurance. Association between the two measures does not establish causation.
05 / Source custody
Evidence behind the series
1 source family, 0 contextual references, and 1 encoded methodology note.
Reusable indicator packetExact rows, stable identifier, and explicit route contract
- Canonical URL
- /indicators/state-health-leader-share
- Indicator filter
- indicator=state-health-leader-share
- License
- Antitrust Radar compilation: CC BY 4.0; upstream terms remain in force
Method notes encoded on rowsNo inferred methodology is substituted
- 01
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.
Indicator evidence guardrail
One measure, one contract
This profile documents one bounded indicator at a time. Its ranks, distributions, histories, and paired views remain inside the stated universe, period basis, source, unit, and methodology; they are descriptive research screens, not legal findings or components of a composite score.
State indicators describe the 2024 ACA-regulated individual health insurance market only. They do not measure a state's overall economy or employer-sponsored insurance.