Regular Season:

18 teams, each plays the others twice - home and away - for a total of 34 games each, over 34 game weeks.

Scoring points:
3 points for a win, 1 point for a draw, 0 points for a loss.

Table order:
1. points won; 2. play-off (only for deciding promotion or relegation); 3. total goal difference; 4. total goals scored; 5. points in head-to-head matches; 6. goal difference in hth matches; 7. goals scored in hth matches.

Relegation to the league:
0-6 teams from Prim B Nacional

Promotion from the league:
1 place: promoted to Prim B Nacional
2-9 place *: enter Promotion Play-off
* - if any of the qualified teams is also to be relegated at the end of the season, it cannot play in the Promotion Play-off, and the best placed team, not already qualified, enters the play-off instead.

Relegation from the league:
Each team's points from participation in the 2015, 2016, 2016/2017 and 2017/2018 Prim B Metro are summed, and that total is divided by the number of games played during that period.
Teams are ranked in a Promedio table, based on the resulting average score.
18 place in the Promedio table: relegated to Primera C

Promedio table order:
1. average points score; 2. play-off.

Promotion to the league:
2 teams from Primera C

Promotion Play-off:

8 teams from the Regular Season contest one place in Prim B Nacional in a knockout format.
Teams are ranked 1st-8th according to their Regular Season standings.

Teams are paired according to their ranking:
1st vs 8th;
2nd vs 7th;
3rd vs 6th;
4th vs 5th.
Winners are decided over one leg, with the higher ranked teams qualifying if score is level after regular time.
The higher ranked teams are hosts.

Teams are ranked 1st-4th according to their Regular Season standings and are paired as follows:
1st vs 4th;
2nd vs 3rd.
Winners are decided over two legs
The higher placed teams from the Regular Season host the second legs.

The two Semi-finals winners meet each other with the winner becoming Promotion Play-off winner.
Winner is decided over two legs.
The higher placed team from the Regular Season hosts the second leg.

Tie-breakers for the Promotion Play-off ties over two legs:
1. aggregate score from the two legs, 2. penalties.

Promotion from the league:
winner: promoted to Prim B Nacional