Consumers Buy Lower-Cost Plans On Covered California, Suggesting Exposure To Premium Increases Is Less Than Commonly Reported

With the notable exception of California, states have not made enrollment data for their Affordable Care Act (ACA) Marketplace plans publicly available. Researchers thus have tracked premium trends by calculating changes in the average price for plans offered (a straight average across plans) rather than for plans purchased (a weighted average). Using publicly available enrollment data for Covered California, we found that the average purchased price for all plans was 11.6 percent less than the average offered price in 2014, 13.2 percent less in 2015, and 15.2 percent less in 2016. Premium growth measured by plans purchased was roughly 2 percentage points less than when measured by plans offered in 2014-15 and 2015-16. We observed shifts in consumer choices toward less costly plans, both between and within tiers, and we estimate that a $100 increase in a plan's net annual premium reduces its probability of selection. These findings suggest that the Marketplaces are helping consumers moderate premium cost growth.