This paper provides a review of public policies affecting the quality of early childhood services for low-income families, focusing on the federally funded Head Start program, federally supported child care, and preschools operated with state education dollars. The characteristics of high quality programs are defined as including: basic health and safety protections; a sufficient number of staff for children; small group size; staff training and consistency; adequate staff salaries and benefits; and, for low income families, comprehensive services for children and their parents. The background and provisions for quality, program standards, monitoring and enforcement, fiscal policies, and training and technical assistance are discussed for Head Start; for the four major federal programs that provide direct assistance for child care: the Social Services Block Grant, the Family Support Act, the Child Care and Development Block Grant; and the "At-Risk" Child Care Program; and for state-funded preschool programs. The following principles are suggested to guide policy regarding quality across publicly funded early childhood programs: (1) all low-income children, regardless of the funding source for care, deserve the best quality of care; (2) all early childhood programs must address the comprehensive needs of children and families; (3) children must have continuity of care; (4) programs should be responsive to parents' schedules. Recommendations for improving the quality of early childhood services for low-income families concludes the report. Contains five references and one note. (DR)