Indonesia has undergone a dramatic policy change with the recent stipulation for making English a compulsory subject in primary schools for the academic year 2027/28. This article examines the teaching of English as a subject in basic education (ESBE) in Indonesia following the policy change, focusing on the challenges faced in the transitionary years from the sixth year of primary level to the first year of secondary level. Using Grounded Theory in the collection of data and analysis, this study investigated the views of Indonesian teachers, school principals, and teacher educators about preparing English learners during the transitionary years of basic education. Findings from the present study demonstrate the complexity of transitions, including the dynamism and challenges entailed. Findings also show that students have been given minimal preparation to transition, occurring at a time when Indonesia is shifting to the policy of compulsory English and to the zonal schooling system. The study also highlights the complex, dynamic, and multidimensional nature of transitions, reflecting the interconnection of internal and external factors in an ecological perspective of language learning where ESBE is integral within the education system.