In Spain there is an increasing trend towards educational policies allowing completely free choice of schools. The purpose of the review described here was to investigate whether school segregation arising from grant maintenance arrangements is an item taken into account when policies for educational equity are under consideration in Spain. It also explores how policies for free choice of school, linked to such grant aid, are reshaping the justifications offered in relation to equity in education. To this end, a systematic literature review (SLR) was carried out, covering from 1990 to the end of 2021 and drawing on four databases reviewed pairwise: Dialnet, Scielo, Scopus and Web of Science.