FORT LAUDERDALE, Fla. (AP) — A study by federal health investigators warns that some foster children are not getting their required medical screenings even though the visits are paid for by Medicaid.

The Health and Human Services’ inspector general study released Monday looked at a random sample of roughly 400 foster children from California, Texas, New York and Illinois. It found nearly 30 percent did not receive one or more of their required health screenings between 2011 and 2012. Of those who did not receive at least one required screening, 12 percent didn’t get an initial screening and 17 percent didn’t receive one or more periodic screenings.

Experts say foster children experience high rates of chronic medical, developmental, and mental health issues. They often face challenges getting access to health care.