One-quarter of privately insured working-age adults have high health care cost burdens relative to their incomes in 2015, according to the Commonwealth Fund Health Care Affordability Index, a comprehensive measure of consumer health care costs. This figure, which is based on a nationally representative sample of people with private insurance who are mainly covered by employer plans, is statistically unchanged from 2014. When looking specifically at adults with low incomes, more than half have high cost burdens. In addition, when privately insured adults were asked how they rated their affordability, greater shares reported their premiums and deductible costs were difficult or impossible to afford than the Index would suggest. Health plan deductibles and copayments had negative effects on many people’s willingness to get needed health care or fill prescriptions. In addition, many consumers are confused about which services are free to them and which count toward their deductible.