This study investigated factors that play a role in the fading effects of prekindergarten programs for economically disadvantaged children. The school adjustment of 1,284 low-income, minority children in prekindergarten and kindergarten programs funded by the government (i.e., Child Parent Center; Head Start) was traced through the third year of school. Data were collected on prekindergarten experience, entering kindergarten cognitive readiness, parental involvement in school activities, assignment to special education, school mobility, grade retention, children's perceptions of academic integration, and cognitive achievement in reading and mathematics. Results of a structural model revealed a network of influences between prekindergarten experience and third-year achievement. The five factors with significant direct effects on third-year achievement, ranked in order of magnitude, were academic integration, entering kindergarten cognitive readiness, retention, parent involvement in school, and school mobility. As expected, retention and mobility had negative effects on achievement. Entering kindergarten cognitive readiness and parent involvement were relatively strong mediators of the effect of prekindergarten on third-year achievement. The mediators of prekindergarten are discussed in regard to enhancing and restricting effects. (Author/RH)