In the extent of educational policies, the age-grade distortion is the indicator that reveals the student s scholastic backwardness related to the year attended at school. Policies to decrease the age-grade distortion called projects and accelerated learning programs are present at the Brazilian scenery since the decade of 1990, autonomously implemented by public school systems, through public-private partnerships and support of the Ministry of Education. Despite the permanence and the capillarity of these projects, few studies discuss the theme interceding quantitative and qualitative data. Furthermore, there is a gap of an impact assessment of these policies and the estimation of their effects by public managers and the academic community. The present work aims to contribute in this perspective and increase the discussion by analysing the policy of flow correction implemented at the municipal schools of Rio de Janeiro in the period of 2009/2014. It presents as well the trajectories of the students - who were or were not affected by the policy - who were enrolled in the fifth year of elementary school in 2010, to the possible scholastic outcomes in 2014. Initially the research was developed from the analysis of the relevant documentation and semi-structured interviews with agents of the municipal education administration. The following analysis points to the database of the enrolments in the municipal system in 2009 conforming to the School Census data (2010, 2011, 2012, 2013 and 2014) in order to understand aspects of design and implementation of the policy, emphasizing on the sociodemographic profiles of students and their learning trajectories. Confirming plentiful previous researches that show that gender and ethnic influence the school backwardness, the results indicates that black children are more likely to age-grade distortion. Given the limited number of spots in the flow correction projects because of the high demand, there is a significant number of delayed students who were not enrolled in flow correction, while others with less than two years of discrepancy and even not delayed entered the projects. Concerning the students trajectories, the data reveal differences among the profiles of students enrolled in flow correction projects and enrolled exclusively in regular classes. These distinctions reverberate in school outcomes suggesting a scholastic segmentation process, which tends to favour students in better social conditions. Although the policy seems to influence the decline of discrepancy in age-grade, during the analysis of courses it was observed that decline rates are not equally distributed among the groups, there seems to be a scale of social vulnerability related to them, with less promising and stigmatized outcomes corresponding to socially vulnerable students. The data points to the fragility of the trajectories that reach high school, which seem to be associated with the policy of accelerated conclusion of the elementary school. Although this outcome at first corroborates the purpose of underlying acceleration to the projects, the high failure rates of these students after enrolling in this academic stage, suggests the fragility of this policy in terms of consolidation of the process of schooling and social mobility of these students.