In an effort to increase the use of preventive services, the Affordable Care Act (ACA) included new requirements for health insurance coverage of a set of recommended preventive services. After September 2010, many private health plans will be required to cover the specified services and to do so at no cost to members. While coverage for some of the ACA mandated services, such as breast and colon cancer screening, is already relatively common, other services are much less likely to be covered by private plans. Moreover, even those who already had coverage for these services are likely to see reductions in cost-sharing under the new provisions. This paper will document the extent to which the 2010 preventive service mandate in the ACA increased receipt of preventive services among non-elderly adults.  Our analysis will use both descriptive and multivariate methods to assess changes in preventive care receipt following the implementation of the new ACA provisions. Data from the National Health Interview Survey (NHIS) and the Behavioral Risk Factor Surveillance System (BRFSS) will be used to measure receipt of a variety of preventive services including cancer and other disease screenings as well counseling services and immunizations. Because individuals are not subject to the policy change at random, we will rely on quasi-experimental design methods to disentangle the effects of the ACA from other concurrent changes. Using the NHIS, we will assess changes in preventive service use between the first and last quarter of 2011 for all adults with private coverage and for different subgroups. We will supplement the NHIS analysis with data from the BRFSS to examine state level patterns of preventive service use before and after the ACA provisions were implemented, exploiting pre-ACA differences in state mandates for preventive care.