This report focuses on the development of reading proficiency during the transition from adolescence to early adulthood. The span of time between the ages of 15 and 24 is a critical period of development for young people. Once compulsory education is completed, individual decisions about post-secondary education, employment and other life choices have to be made with major consequences for future learning and employment outcomes. A good foundation in reading proficiency facilitates success in specialised education during higher education or during job-related training. Since reading proficiency is not the goal of such specialised or professional learning, reading skills may begin to atrophy. So both learning gains and losses need to be considered as human capital is developed. Canada’s investments in PISA, as well as in longitudinal data and reassessment of reading proficiency, provides insights into the importance of individual reading proficiency and later outcomes, such as educational attainment, further learning, employment and earnings. Therefore, this report makes a vital contribution to the understanding of learning gains between the ages of 15 and 24 and their impact on such outcomes, and provides a basis for evidence-based policy and strategic investments by the community of countries participating in PISA