According to a recent report, 31 million adults

were considered underinsured in 2014, because although they had health insurance for a full year, they had high deductibles or out-of-pocket expenses relative to their income. Of these:

• 51% had trouble paying medical bills or were paying off medical debt over time
• 38% either had trouble paying or couldn’t pay their medical bills
• 34% had medical debt they were paying off over time
• 23% had been contacted by a collection agency over unpaid medical bills
• 22% said they had to change their way of life in order to pay their medical bills

Source: "31 Million People Were Underinsured in 2014; Many Skipped Needed Health Care and Depleted Savings to Pay Medical Bills," The Commonwealth Fund News Release, May 20, 2015, http://www.commonwealthfund.org/publications/press-releases/2015/may/underinsurance-brief-release