American society has long realized the importance of education as a tool for social and economic mobility and therefore has supported free public education with taxpayer dollars. Understanding that every child is entitled to an education appropriate to his or her needs, to varying extents state legislatures have recognized the importance of providing funding to educate children at risk of academic failure. Such children include not only those with disabilities but also children affected by poverty, urbanicity, race, limited English proficiency, and family characteristics such as low parental educational attainment. Given the range of risk factors facing public schools and their potential effect on academic achievement, the level and extent of state funding for at-risk students is of growing concern. In particular, the funding of such programs represents an important but often overlooked theoretical concept in the analysis of state education funding systems: vertical equity. The purpose of this article is to reinvigorate the discussion of vertical equity through an assessment of the funding systems in four states (California, New York, Texas, and Wisconsin) that ascertains how and to what extent risk factors are addressed. The state funding systems analyzed in this article address the disparate needs of at-risk children through a variety of mechanisms, many of which fall into two broad categories: They are either weighting factors added to the basic aid formula or categorical grants-in-aid. A key question for policymakers is to ascertain how many additional resources are needed to ensure that at-risk students succeed. Though this question is beyond the scope of this study, it is hoped that the results presented here will stimulate future research into the relationship of funding levels to student outcomes. In an educational environment in which many schools and districts struggle to meet federal and state mandates with limited funds, it is imperative to build a better understanding of the ability of funding for at-risk children to increase the vertical equity of state school finance systems. This study provides a first glimpse into this complex policy issue. (Contains 5 tables and 27 footnotes.)