Covered California Open Enrollment 2013–2014: Lessons Learned

Covered California officials said they were "fortunate to have access to a robust data model," the California Simulation of Insurance Markets (CalSIM), to help provide early enrollment projections and guide their program planning activities. CalSIM is a micro-simulation model that uses a wide range of official data sources, including the California Health Interview Survey.

CalSIM is a microsimulation model developed by the Center and UC Berkeley's Center for Labor Development and Education which uses demographic factors from the California Health Interview Survey (CHIS) and other sources to develop eligibility and enrollment projections based on various demographic factors, such as race and ethnicity.

For instance, CalSIM projected what various elements of the Affordable Care Act would have on eligibility and enrollment, such as what share of the population was eligible for subsidies, or what share what qualify for Medi-Cal. In May 2014, CalSIM released a revised model with updated enrollment projections through 2019.