The teams were divided into three zones with ten teams and one zone with nine teams (a total of 39 teams) in each zone and it was played in a round-robin tournament whereby each team played each one of the other teams two times. The teams placed 1º to 4º from each zone qualified for the Second Stage. The remaining twenty three teams qualify for the Revalida Stage.[1]
Championship stages
Second stage
The teams were divided into two zones with eight teams each and it was played in a round-robin tournament whereby each team played each one of the other teams one time. The teams placed 1º and 2º and the best 3º team from the two zones qualified for the Third Stage or Pentagonal Final. The remaining team placed 3º qualify for the Third Phase of the Revalida Stage. The other ten teams qualify for the Second Phase of the Revalida Stage.
Third stage
The five teams that qualified for the third stage or Pentagonal Final play in a round-robin tournament whereby each team played each one of the other teams one time. The winner was declared champion and automatically promoted to the Primera B Nacional. The other four teams qualify for the Fourth Phase of the Revalida Stage.[1]
Revalida Stages
The Revalida Stage is divided in several phases: First, the twenty three teams that did not qualify for the Championship Stages were divided into the same four zones of the First Stage and it was played in a round-robin tournament whereby each team played each one of the other teams two times. The team placed 1º of each zone qualified for the Second Phase. The second phase is played between the four teams that qualified from the First Phase and the ten teams that qualified from the Second Stage of the Championship Stage. The seven winners qualify for the Third Phase.
The Third Phase is played between the seven teams that qualified from the Second Phase and the team that qualified from the Second Stage of the Championship Stage. The four winners qualify for the Fourth Phase.
The Fourth Phase is played between the four teams that qualified from the Third Phase and the four teams that qualified from the Third Stage of the Championship Stage. The four winners qualify for the Fifth Phase. The Fifth and Sixth Phase is played between the remaining teams and aims to get the Second promotion to the Primera B Nacional.
Relegation
After the First Phase of the Revalida Stage a table was drawn up with the average of points obtained in the First Stage and the First Phase of the Revalida Stage. It is determined by dividing the points by the number of games played and the bottom team of each four zones was relegated to the Torneo Federal B. Also, another table was drawn up with the remaining teams that played the Revalida Stage and the bottom four teams were relegated to the Torneo Federal B. Giving a total of eight teams relegated.[1]
Updated to match(es) played on March 19, 2018. Source: AFA Rules for classification: 1) points; 2) goal difference; 3) goals scored; 4) draw of lots. Notes:
^ abVilla Mitre ahead of Ferro Carril Oeste (GP) on goal difference: Villa Mitre -4 goal difference; Ferro Carril Oeste (GP) -6 goal difference
Updated to match(es) played on March 19, 2018. Source: AFA Rules for classification: 1) points; 2) goal difference; 3) goals scored; 4) draw of lots. Notes:
^ abcGoals scored: Unión (S) 9 goals; Sportivo Belgrano 8 goals; Crucero del Norte 7 goals.
^ abChaco For Ever ahead of Gimnasia y Tiro on goal difference: Chaco For Ever -3 goal difference; Gimnasia y Tiro -7 goal difference.