This data set presents annual enrollment counts of Medicaid and CHIP beneficiaries by major eligibility group (children, adult expansion group, adult, aged, persons with disabilities, or COVID newly-eligible). There are three metrics presented: (1) the number of beneficiaries ever enrolled in each major eligibility group over the year (duplicated count); (2) the number of beneficiaries enrolled in each major eligibility group as of an individual’s last month of enrollment (unduplicated count); and (3) average monthly enrollment in each major eligibility group.

These metrics are based on data in the T-MSIS Analytic Files (TAF). Some states have serious data quality issues, making the data unusable for calculating these measures. To assess data quality, analysts used measures featured in the DQ Atlas. Data for a state and year are considered unusable or of high concern based on DQ Atlas thresholds for the topic Eligibility Group Code. Please refer to the DQ Atlas at http://medicaid.gov/dq-atlas for more information about data quality assessment methods.

Some cells have a value of “DS”. This indicates that data were suppressed for confidentiality reasons because the group included fewer than 11 beneficiaries.