4 teams qualify for the competition:
the 17th and 18th placed teams in the Promedio table of the 2011/2012 Prim B Nacional;
the 2nd placed team in the 2011/2012 Prim B Metro;
the 2nd placed team in the 2011/2012 Argentino A.
4 teams contest 2 places in 2012/2013 Prim B Nacional in a knockout format.
Teams are paired as follows:
a) if the two Prim B Nacional teams are of different affiliation with AFA (regardless of Promedio table order):
Prim B Nacional team with direct affiliation vs the Prim B Metro team;
Prim B Nacional team with indirect affiliation vs the Argentino A team.
b) if the two Prim B Nacional teams are of the same affiliation with AFA (regardless of type of affiliation):
17th in the Promedio table in Prim B Nacional vs the Argentino A team;
18th in the Promedio table in Prim B Nacional vs the Prim B Metro team.
Winners are decided over two legs, with the Prim B Nacional teams hosting the second legs.
Tie-breakers for the knockout matches:
1. aggregate score from the two legs, 2. level of competition in which the team participates (Prim B Nacional is higher level than Prim B Metro and Argentino A).