Health care expenditure patterns are described using a sample of 2,767 adolescents aged 10 to 18 years from the National Medical Care Utilization and Expenditure Survey. Average total per capita health care expenditures were $525. Average out-of-pocket expenses were $151 in 1988 dollars. The burden of out-of-pocket expenses was distributed unevenly among the families of adolescents. The 10% of adolescents with the highest expenses accounted for 65% of all out-of-pocket expenses. The presence of health insurance coverage greatly reduced the risk of incurring burdensome out-of-pocket expenses. Health policy interventions to improve health insurance coverage of adolescents are discussed.