[영문]Child welfare policy and practice have increased their focus on adoption for those children who cannot rapidly be reunified from foster care. The burgeoning numbers of children receiving adoption subsidies have led some states to be concerned about or even to curtail adoption subsidy levels. Yet, little is known about how the cost of foster care compares to that of adoption. This study uses longitudinal adoption subsidy and foster care placement data to estimate the relative costs of foster care and adoption for a statistically matched group of children. The data show that a sizable proportion of children who are not adopted will leave foster care but that an offsetting proportion of the children who remain will be transitioned to substantially more expensive placements than those used by adopted children. On balance, adoption achieves substantial governmental savings.