The eighteen teams joined the preliminary round, played as mini-tournaments with three teams in each group, where only the first qualified team will advance to further stages.
The winners of groups A, B, C and D joined the intermediate stage while the winners of the groups E and F directly qualified for the semifinals.
The play-off between Andalusia and Ceuta was played on 27 January and 10 February 2016, while the matches between Asturias and Extremadura were played on 10 and 24 February 2017.