1  How Well Does Insurance Coverage Protect Consumers from Health Care Costs? Commonwealth Fund, October 18, 2017. The share of U.S. adults who were underinsured in 2016 has doubled since 2003. people were underinsured in 2016 More than ¼ of adults with health insurance were underinsured in 2016. Half of underinsured adults who had problems paying their medical bills or had medical debt said they used up all their savings to pay bills. 41 million More than half of the underinsured said they had trouble paying their medical bills. 13% of adults enrolled in a private plan had a deductible more than $3,000. Workers in companies with 100+ employees saw one of the sharpest increases in the underinsured rate. 45% of the underinsured went without needed care because of costs. 2x 44% of the underinsured were covered by federal marketplace plans. of the underinsured were covered through employer plans. 23% of adults with individual marketplace plans 25% had deductibles equaling 5% or more of their income. 22% 40% of underinsured adults now have a lower credit rating because of those bills. In October 2017, the Commonwealth Fund issued a report1 on the sharp increase in the number of underinsured Americans. The report found that people with all types of health insurance can be underinsured. Here are some of the sobering statistics unveiled in the report.