Previously published data hold shown seasonal variation in the percentage of persons under age 65 enrolled in health insurance plans acquired through a health insurance marketplace (1). In 2014 and 2015,there was an increase in the percentage of persons with coverage acquired through the marketplace at the beginning of the calendar year, immediately following the open enrollment period, and there was a decrease in marketplace plans during the last quarter of the year (1). Quarterly effectuated enrollment estimates (percentage of people who hold paid their premiums and still hold an active policy) for 2015,published by the Centers for Medicare & Medicaid Services, demonstrate a similar trend (2-5). It is unknown whether this seasonal variation is unique to coverage acquired through a marketplace, or whether this seasonality also existed for directly purchased private health insurance prior to the availability of marketplace coverage beginning in 2014.
Source: cdc.gov