Turnover in Zero-Premium Status Among Health Insurance Marketplace Plans Available to Low-Income Enrollees.

Importance: Recent subsidy enhancements in Affordable Care Act (ACA) Marketplaces made many low-income enrolles (below 150% of the federal poverty level [FPL]) eligible for 2 free silver-tier plans. eligible for 2 free silver-tier plans. However, an unintended consequence of this structure is that the identity of which silver plans are free will often "turn over" between years, requiring that enrollees actively initiate premium payment (or lose coverage). The prevalence of this free-plan turnover is not known. Objective: To measure the prevalence of free-plan turnover in ACA Marketplaces and to estimate how many enrollees below 150% of FPL are likely to be affected. Design Setting and Participants: This observational cross-sectional study used data on plan offerings and premiums in 33 state ACA Marketplaces using HealthCare.gov in 2021 and 2022, along with estimates of county-level enrollee characteristics and plan selection patterns. The enrollment-weighted share of county markets affected by free-plan turnover was quantified, along with the association of turnover with enrollee and market characteristics. Estimates of the number of affected low-income enrollees were calculated using the data plus statistics reported in past research. Data were analyzed from November 21, 2021, to February 28, 2022. Results: This study found that turnover of zero-premium plans was quite common, with 93% of HealthCare.gov counties (weighted by enrollment) experiencing at least 1 zero-premium plan in 2021 turning over to nonfree in 2022; 84% of counties experienced turnover of all $0 silver plans from 2021 to 2022. This turnover affected an estimated 1.36 million people with incomes below 150% of FPL. Turnover was more common in counties with a higher share of non-White enrollees, in Medicaid nonexpansion states, in counties with more carriers, and in counties with changes in the number of offered plans. Conclusions and Relevance: The findings of this cross-sectional study suggest that owing to the prevalence of zero-premium plan turnover, many low-income ACA enrollees faced elevated risk of disenrollment at the start of 2022. Outreach to affected enrollees and other actions to encourage coverage retention and midyear reenrollment could help mitigate coverage losses.