We evaluate the effects of state policy design features on SCHIP take-up rates and on the degree to which SCHIP benefits crowd out private benefits. The results indicate overall program take-up rates of approximately 10 percent. However, there is considerable heterogeneity across states, suggesting a potential role of inter-state variation in policy design. We find that several design mechanisms have significant and substantial positive effects on take-up. For example, eliminating asset tests, offering continuous coverage, simplifying the application and renewal processes, and extending benefits to parents all have sizable and positive effects on take-up rates. Mandatory waiting periods, on the other hand, consistently reduce take-up rates. In all, inter-state differences in outreach and anti-crowd-out efforts explain roughly one-quarter of the cross-state variation in take-up rates. Concerning the crowding out of private health insurance benefits, we find that between one-quarter and one-third of the increase in public health insurance coverage for SCHIP-eligible children is offset by a decline in private health coverage. We find little evidence that the policy-induced variation in take-up is associated with a significant degree of crowd out, and no evidence that the negative effect on private coverage caused by state policy choices is any greater than the overall crowding-out effect. This suggests that states are not augmenting take-up rates by enrolling children that are relatively more likely to have private health insurance benefits.