Every State in the United States has a public child protection system (CPS) that receives and responds to reports of child abuse and neglect. Cases that receive services from CPS on an ongoing basis constitute a minority of those referred and are made up of families who are judged to be at highest risk. Preventive services provided by CPS to high-risk families typically include, case management and supervision, as well other preventive services. However, some States and localities invest some resources into services to prevent maltreatment among lower-risk families, families who do not meet the criteria for ongoing protective services. Most preventive services for lower-risk families often focus on increasing parents' understanding of the development stage of childhood and on improving their child-rearing competencies through education. CPS has an important role to play in preventing maltreatment not just among the relatively high-risk cases, but also among the lower-risk families. This article examines preventive efforts for high-risk families, cases opened for ongoing services with CPS and preventive efforts for lower-risk families, not opened or kept open for services with CPS. 1 table and 40 endnotes