This research examines the effectiveness of two national awareness campaigns in their ability to increase rates of insurance coverage among low-income children potentially eligible for public health insurance programs. The campaigns evaluated are the 2005 and 2006 Robert Wood Johnson Foundation's Cover the Uninsured Week and the Back to School Campaign. Differential rates of exposure to earned media (television, radio, and print news coverage) are estimated for large metropolitan area in the United States. The exposure variables are matched to children in the Current Population Survey (CPS). Controlling for relevant individual and family characteristics and metropolitan area, the impact of each type of exposure is estimated. Two outcomes are considered: a campaign's ability to encourage enrollment among those uninsured prior to exposure and its ability to sustain coverage among those that are already insured in the pre-exposure period. The campaigns are posited to assist in overcoming one of three types of cost to enrollment: information, process, and outcome costs (perceived outcome) of enrollment. The results are also considered in light of the knowledge gap hypothesis.