(AP) Illinois is among a dozen states where new enrollees have surpassed projections for the expansion of Medicaid under President Barack Obama’s health law. The surge has lifted the number of insured citizens, but spurs worries about future costs to taxpayers. Illinois and Cook County eventually will have to bear 10 percent of the cost of expanding the safety-net insurance program for the poor. The federal government agreed to pay all costs for the expansion through 2016, but it will begin lowering its share in 2017. Enrollment has more than doubled the projection of former Illinois Gov. Pat Quinn’s administration. The prediction was for 298,000 people to sign up in 2015. But 623,000 newly eligible Illinoisans have enrolled. Sign-ups have outstripped projections in at least a dozen states.