The CMS transparency data public use files display data reported by issuers that participate in the ACA individual market in healthcare.gov states. The data posted by CMS includes issuers of major medical qualified health plans as well as those that only offer stand-alone dental plans (SADPs), and issuers that offer both types of plan. For issuers that offer both medical plans and SADPs under the same HIOS issuer ID, the data posted by CMS do not separate medical claims from dental claims. The data posted by CMS include instances of missing data and suppressed data, as well as some data that appear to be invalid (for example, an issuer with more denials than claims).

For this analysis, we condensed the transparency public use files into working data files, posted with this brief, that separate issuers of major medical plans and SADPs, and separate issuers with complete data from those with missing or invalid data. We categorized issuers as SADP-only in a given year and state if more than one third of an issuer’s enrollment in that year and state is in SADPs (based on CMS plan-level enrollment public use files), or if the fields “Issuer Name” or “URL” provided in the transparency data contain the word “dental”.

Issuers were excluded for missing data if “Claims Received,” “Claims Denied,” or “Enrollment Data” is missing (including cases where these fields show “*” or “N/A”). Issuers were excluded if “Claims Received” or “Enrollment Data” is less than 1000 (including instances of suppressed data). Additionally, one issuer was excluded for showing more “Claims Denied” than “Claims Received.”

There is a data dictionary on the first sheet of each of the three working data files posted with this brief.

According to the CMS enrollment data and the 2017 Individual Market Medical data from healthcare.gov, 9.43 million unique individuals had at least one effectuated enrollment in a healthcare.gov state during 2017. The 2017 CMS transparency file includes issuers that account for 8.82 million (94%) of these enrollees, and includes complete claims denials data for 8.57 million (91%) of these enrollees.