One-in-5 US adults say they are burdened by medical debt and half of them are unable to pay the debt at all, federal health officials said. Lead author Robin Cohen of the Centers for Disease Control and Prevention\'s National Center for Health Statistics said health insurance -- public or private -- frequently determines whether families can pay for their medical expenses. In the first six months of 2011, one-third of people were in a family experiencing financial burden of medical care. One-in-5 were in a family having problems paying medical bills, 25 percent were in a family paying medical bills over time and 10 percent were in a family that had medical bills they were unable to pay at all, the report said. \"When 1-in-5 Americans were in medical debt it\'s clear that we\'re not doing enough to make health insurance affordable. Soon, federal law will require every American to have insurance, but nothing controls what health insurers can charge,\" Carmen Balber of the Consumer Watchdog Campaign in California said in a statement. \"States need the power to say no to excessive health insurance premium hikes.\" A ballot initiative sponsored by CWC for the November ballot in California would require insurance companies to justify rate increases, under penalty of perjury, before higher rates can take effect. Regulators would have the power to reject or modify unreasonable premium rates, and limit the amount of wasteful overhead, profit and executive compensation that insurance companies may pass on to consumers, Cohen said.