The recession is driving up enrollment in Medicaid at higher than expected rates, threatening state budget gaps even as Congress and the White House seek to expand the government health insurance program, according to a survey. The annual survey of state Medicaid directors, conducted for the Kaiser Family Foundation's Commission on Medicaid and the Uninsured, found that the program had been spared the worst effects of massive state budget shortfalls because of federal aid in the stimulus package. But it also revealed concerns about what will happen when that relief ends in 2010, reports the New York Times.