Between 2013 and 2017, the share of children whose families had problems paying medical bills declined by 20 percent, but one in six children (an estimated 13.0 million) still lived in a family with problems paying medical bills in 2017. Low-income children were more likely than higher-income children to live in families with problems paying medical bills, and four in five low-income children in families with such problems had either uninsurance or health problems in the family. Most also experienced other financial hardships, including family food insecurity and worries about monthly bills, rent, or housing costs. These findings suggest currently low levels of uninsurance among children are not sufficient to protect them from family financial insecurity associated with medical bills.