Studies in the US, the UK and Europe found children born close to the cut-off date for the start of school year face disadvantage in terms of educational attainment. This is attributed to the fact that pupils born shortly before the cut-off date are almost a year younger than many of their classmates. They are in an earlier stage of their intellectual, emotional and physical development and are thus relatively disadvantaged. Differences in growth and health outcomes by birth month have been found in other studies. This paper tests whether long-term educational and health disadvantages of individuals born just before the start of school year cut-off date of July 1st exist in Northern Ireland. The analysis is based on a c.28 per cent representative population sub-sample of young people aged 12-18 in 2001 in the Northern Ireland Longitudinal Study (NILS) with linked 2001 and 2011 Census records. Findings indicate no educational or health disadvantages over a decade for individuals born in May and June.