English language instruction in New Zealand's Māori-medium schools is controversial, with many schools either excluding it from their curriculum or adopting a tokenistic approach. Yet, how Māori-medium educators can best support their students' academic English language growth is still an under-researched and unresolved question. This paper reports on a project involving the English language transition programmes of three Māori-medium primary schools. Interviews and observations of key personnel within these schools revealed the components of their programmes, their perceptions of the need for English transition education and the issues they were facing in implementing English language instruction. The project found a direct relationship between levels of student language attainment and the quantity and quality of exposure to English instruction. Where an English programme occupied a significant place in a school's timetable and was staffed by teachers knowledgeable about the learning needs of bilingual students and how best to attend to these, the result was higher literacy scores and more satisfied students. This paper argues that planning English language outcomes for Māori-medium students is essential if becoming biliterate is an important aim. This planning must also be long-term, across all 13 years of the students' education.