Summary: Low- and moderate-income expectant mothers, their infants, and children with special health care needs are the intended beneficiaries of Maternal and Child Health Services block grants. This important federal program helps states deliver basic health care services, like prenatal and postpartum care, to those who might otherwise do without. GAO examined the current formula under which program funding--$453 million in fiscal year 1990--is allocated among the 50 states and the District of Columbia. Its recommendation is that Congress adopt a formula that distributes state funding according to the following three factors: concentration of children at risk, costs of providing health care services, and states' ability to finance maternal and child health services. In redesigning the formula, however, Congress will need to strike a balance between equity for beneficiaries and state taxpayers. GAO's weighing of these two concerns in its example of a new allocation formula shows one way Congress' preferences could be implemented.