A national language policy reflects how a state looks at the languages used by its people. It assigns certain roles to languages, and addresses the issues of language education and language of education. Pakistan, a multilingual country, has yet no language policy at national level. This absence of policy has caused many issues, including the medium of instruction (MoI). Since the country is currently developing a single national curriculum, its success largely depends on resolving the issue of the medium of instruction. the paper, motivated by the same issue, introduces the problem, then, after discussing some major linguistic challenges faced by the country, it spotlights the difference between the Constitution (1973) and the National Education Policy on the issue of MoI. The paper takes insights from Integrative Framework (Hornberger, 2006) of language planning and policy, and Stage Actor Model (Zhao & Baldauf, 2012), to discuss actor agency and their role in solving the problem. The paper proposes a late-exit transitional bilingual model to address the issue of MoI in the country. It concludes with recommendations for a well-framed national language policy capable to de-stigmatise the national language Urdu, to give due recognition to regional or autochthonous languages, and to provide clear guidelines about the MoI in the formal education system of the country.