This article derives from a qualitative study that employed a sociocultural perspective to investigate the mediation of institutional policies on teachers' classroom practices of assessment for learning in one public and one private university in Vietnam. Data included observations of classrooms, interviews with teachers, executive officers and students, and documents such as institutional policies, curriculum, and tests. Findings included the impact of institutional language policies on language assessment practices, forms of institutional interactions, workplace conditions and compensation, and English language programme design. The study highlights how the Vietnamese national Project 2020 language policies are mediated by higher education institutions to manifest in particular ways in the micro-level classroom practices of teachers. Of interest is English language education and its provision in the established public sector as well as the non-public sector that is a growing feature of marketised higher education in Vietnam. The institutional differences and similarities are identified to illustrate the need for new working conditions and practices to assist policy makers and teachers as they seek to fulfil the English language priorities of the country.