[영문]To determine whether socioeconomic disparities exist in the financial burden of out-of-pocket (OOP) health care expenditures for families with children, and whether health insurance coverage decreases financial burden for low-income families.The Household Component of the 2001 Medical Expenditure Panel Survey.Cross-sectional family-level analysis. We used bivariate statistics to examine whether financial burden varied by poverty level. Multivariate regression models were used to assess whether family insurance coverage was associated with level of financial burden for low-income families. The main outcome was financial burden, defined as the proportion of family income spent on OOP health care expenditures, including premiums, for all family members.We aggregated annual OOP expenditures for all members of 4,531 families with a child qqqlt;18 years old. Family insurance coverage was categorized as follows: (1) all members publicly insured all year, (2) all members privately insured all year, (3) all members uninsured all year, (4) partial coverage, or (5) mix of public and private with no uninsured periods.A regressive gradient was noted for financial burden across income groups, with families with incomes qqqlt;100 percent of the Federal Poverty Level (FPL) spending a mean of