Kaiser Family Foundation

The ASEC asks respondents about their health insurance coverage throughout the previous calendar year. Respondents may report having more than one type of coverage. In this analysis, individuals are sorted into only one category of insurance coverage using the following hierarchy: Medicaid: Includes those covered by Medicaid, the Children’s Health Insurance Program (CHIP), and those who have both Medicaid and another type of coverage, such as dual eligibles who are also covered by Medicare. Medicare: Includes those covered by Medicare, Medicare Advantage, and those who have Medicare and another type of non-Medicaid coverage where Medicare is the primary payer. Excludes those with Medicare Part A coverage only. Employer: Includes those covered by employer-sponsored coverage either through their own job or as a dependent in the same household. Other Public: Includes those covered under the military or Veterans Administration. Non-Group: Includes individuals and families that purchased or are covered as a dependent by non-group insurance. Uninsured: Includes those without health insurance and those who have coverage under the Indian Health Service only. For example, a person having Medicaid coverage in the first half of the year but employer-based coverage in the last months of the year would be categorized as having Medicaid coverage in this analysis. N/A: Estimates with relative standard errors greater than 30% are not provided.

Enrollment is measured in life-years (which is member months divided by 12). Enrollment data approximate the number of people enrolled in comprehensive major medical insurance and mini-med plans. Plans that shared a parent company or insurer group were collapsed into one insurer for the purposes of this analysis. 

The ASEC asks respondents about their health insurance coverage throughout the previous calendar year. Respondents may report having more than one type of coverage. In this analysis, individuals are sorted into only one category of insurance coverage using the following hierarchy: Medicaid: Includes those covered by Medicaid, the Children’s Health Insurance Program (CHIP), and those who have both Medicaid and another type of coverage, such as dual eligibles who are also covered by Medicare. Employer: Includes those covered by employer-sponsored coverage either through their own job or as a dependent in the same household. Other Public: Includes those covered under the military or Veterans Administration as well as nonelderly Medicare enrollees. Non-Group: Includes individuals and families that purchased or are covered as a dependent by non-group insurance. Uninsured: Includes those without health insurance and those who have coverage under the Indian Health Service only. For example, a person having Medicaid coverage in the first half of the year but employer-based coverage in the last months of the year would be categorized as having Medicaid coverage in this analysis. N/A: Estimates with relative standard errors greater than 30% are not provided.

The ASEC asks respondents about their health insurance coverage throughout the previous calendar year. Respondents may report having more than one type of coverage. In this analysis, individuals are sorted into only one category of insurance coverage using the following hierarchy: Medicaid: Includes those covered by Medicaid, the Children’s Health Insurance Program (CHIP), and those who have both Medicaid and another type of coverage, such as dual eligibles who are also covered by Medicare. Employer: Includes those covered by employer-sponsored coverage either through their own job or as a dependent in the same household. Other Public: Includes those covered under the military or Veterans Administration as well as nonelderly Medicare enrollees. Non-Group: Includes individuals and families that purchased or are covered as a dependent by non-group insurance. Uninsured: Includes those without health insurance and those who have coverage under the Indian Health Service only. For example, a person having Medicaid coverage in the first half of the year but employer-based coverage in the last months of the year would be categorized as having Medicaid coverage in this analysis. N/A: Estimates with relative standard errors greater than 30% are not provided.

The Herfindahl-Hirschman Index (HHI) is a measure of how evenly market share is distributed across insurers in the market. HHI values range from 0 to 10,000, with an HHI closer to zero indicating a more competitive market and closer to 10,000 indicating a less competitive market. An HHI index below 1,000 generally indicates a highly competitive market; an HHI between 1,000 and 1,500 indicates an unconcentrated market; a score between 1,500 and 2,500 indicates moderate concentration; and a value above 2,500 indicates a highly concentrated (uncompetitive) market. N/A: Data not available.