This paper examines the introduction of premiums into the SCHIP program in Kentucky. Kentucky introduced a $20 monthly premium for SCHIP coverage for children with family incomes between 151 percent and 200 percent of the federal poverty level in December 2003. Administrative data between 2001 and 2004 is used to estimate a Cox proportional hazard model that predicts enrollment duration in this premiumpaying category. The results suggest that a premium reduces the length of enrollment, with the impact concentrated in the first three months after the introduction of the premium. Similar results are not found for the non-premium-paying category. © 2007 by the Association for Public Policy Analysis and Management