The objective of this paper is to show the way in which the educational policies implemented in Higher Secondary Education (EMS) in Mexico, led to the omission of the Federal High Schools for Cooperation (PREFECO for its acronym in Spanish) as a public subsystem. This omission had repercussions in the closure of schools and exacerbated the precarious working conditions of the teachers who work in that school subsystem. The paper analyzes the policies directed at the EMS during the 2008-2019 period in order to identify the causes that originated the main changes in the subsystem. The case of the PREFECO’s of the state of Morelos is contextualized and the labor conditions of their teachers. For the analysis of the official documents, some guidelines of the historical-descriptive method were retaken. To contextualize the conditions of the teachers, a questionnaire was applied and descriptive statistics were used for the analysis.