The eighteen group winners had the opportunity to be promoted directly to Segunda División B.
The nine losing clubs entered the play-off round for the last nine promotion spots.
The twenty-seven winners advanced with the nine losing clubs from the champions' series to determine the eighteen teams that entered the last two-legged series for the last nine promotion spots.
In all the playoff series, the lower-ranked club played at home first.
Whenever there was a tie in position (e.g. like the group winners in the champions' series or the third-placed teams in the first round), a draw determined the club to play at home first.