OBJECTIVES: The Affordable Care Act (ACA) established the health insurance Marketplaces to provide people the opportunity to obtain health care coverage. Assisters have worked with people who may have difficulty understanding the new system and selecting the right plan. This study described the availability of assisters and examined the relationship between assisters and Marketplace enrollment.

METHODS: The 2016 Marketplace enrollment data, 2016 Small Area Health Insurance Estimates data, and a database of assister programs constructed using healthcare.gov were analyzed at the county level. The hierarchical generalized linear model was used to examine the effect of assisters on Marketplace enrollment.

RESULTS: The study analyzed 2,261 counties nested within 34 states. About half of counties did not provide assisters at all. Counties had the average 45.8 % of the potential Marketplace enrollees but had only 11.4 % of actual enrollment among the potential enrollees. The Marketplace enrollment among the non-elderly individuals was positively associated with the number of assisters and Medicaid expansion.

CONCLUSIONS: Assisters were hardly available despite their critical role in the Marketplace. The expansion of assisters will improve Marketplace enrollment by educating people on financial assistance and increasing awareness of the Marketplace.