The inability of the United States to narrow the achievement gap stems to a large extent from school reform initiatives that neglect the specific conditions in the lives of low-income students that contribute heavily to inadequate school performance. A new consensus is emerging that a more effective approach would be to prevent the achievement gap from emerging in the first place. This strategy would start with high-quality early childhood experiences and include adequate health care and high-quality after-school and summer programs, as well as school improvement. This second in a five part series, an analysis, estimates the cost of public policies to substantially narrow the achievement gap, if these policies begin early in the development cycle and build on previous success, rather than attempting to remediate past failures. The report models appropriate investments in prenatal, neonatal, infant, and early childhood development, followed by appropriate investments later to sustain the effects of such early interventions. It assumes that such a strategy could significantly inhibit development of the achievement gap in the first place, making it easier to sustain greater equality in outcomes through the school years. The full program covers a span of 18.5 years, from the beginning of the second trimester of pregnancy to 18 years of age. It would take 18.5 years to implement fully, because as each cohort matures, new services are added in each year. And each year, a new cohort is added to the model. The model is comprised of the following components: The prenatal period is devoted to ensuring that all underprivileged pregnant women receive adequate prenatal and obstetric care, increasing the likelihood that each child is born with capacity to flourish. Family (parental support) services also begin in the prenatal period and continue throughout the full 18½ years of the child's development cycle. These services include visiting nurses from the second trimester of pregnancy until the child's third birthday, parent access to continuing education from the neonatal and infancy year until the child's 18th birthday, visiting home literacy coaches for low-income children ages three, four, and five, and school-based comprehensive service coordinators. The neonatal and infancy year of the model, covering newborns to one year of age, introduces highquality early childhood care and education that continues through age two. The model provides prekindergarten for ages three and four. Also introduced in the neonatal and infancy year is routine and preventive pediatric care, and routine and preventive dental and vision care are added soon thereafter. The program models all of these costs as provided in a school-based health clinic and continuing until the child's 18th birthday, which the model assumes occurs at the end of the normal senior year of high school. The model also provides for high quality after-school and summer programs from age five (kindergarten) to age 18. The model assumes that the children eligible for these services are those who are eligible for the federally subsidized lunch program. In 2008, approximately one-third of all children in New York State were in such households. For each underprivileged family and child in New York City that takes advantage of all services recommended and modeled in this report, the estimated cumulative lifetime (to age 18) cost is about $290,000, or an average annual per child cost of about $15,700. If these costs were converted to New York State dollars, the lifetime per child cost would be approximately $256,000 and the average annual per child cost would be about $13,900. Assuming conservatively that each child would access 75% of the available services, the New York City annual cost would be approximately $11,800 per child and the New York State cost approximately $10,400. Appended to this report are: (1) Will Implementation of This Model Reduce Special Education Expenditures?; and (2) Are Services Provided in This Model Already Covered by Medicaid?. Endnotes and a bibliography are also provided. [The authors are grateful to the Smart Family Foundation, the James and Judith K. Dimon Foundation, and the Robert Sterling Clark Foundation for support of this research. For "Providing Comprehensive Educational Opportunity to Low Income Students. Part 1: A Legal Framework," see ED573117; for "Providing Comprehensive Educational Opportunity to Low Income Students. Part 3: How Much Does New York City Now Spend on Children's Services?, see ED573121; for "Providing Comprehensive Educational Opportunity to Low Income Students. Part 4: What Are the Social and Economic Returns?," see ED573122; and for "Providing Comprehensive Educational Opportunity to Low Income Students. Part 5: A Proposal for Essential Standards and Resources. A Report of the Task Force on Comprehensive Educational Opportunity," see ED573123.]