2008–09 Primera División A season

The format for the 2008–09 season changed from 2 groups of 12 to 3 groups of 9 teams. This gave the opportunity and the number increased from 24 to 27, many teams served as reserve teams from teams in D1.

Changes for the 2008–09 season

 * Coatzacoalcos moved to Orizaba and was rebranded Orizaba after Apertura 2008
 * Veracruz were demoted from Primera División
 * Indios were promoted to Mexican Primera Division
 * Irapuato won promotion to Primera División A when Pachuca Jr. did not meet the qualifications for promotion.

Added teams
 * Atlante Chetumal
 * Mérida FC
 * Chihuahua
 * Club Tapatio From Morelia B

Torneo Apertura
The Primera División A Apertura 2008 is a Mexican football tournament, one of two short tournaments held each year. It began on July 18, 2008, and ran until December 7, 2008. The reigning champions, León, were eliminated in the quarterfinals by Irapuato on a 2–1 two-leg aggregate, and thus could not successfully defend their Clausura 2008 title. Querétaro won the tournament, defeating Irapuato on a 2–0 two-leg aggregate, and will earn a spot into the promotional playoff held after the end of the Clausura 2009 season, where the winners of the two tournaments meet in an effort to gain promotion to the Primera División.

After winning the 2008 promotional playoff against León, the Indios were promoted to the Primera División. Veracruz were relegated to the Primera División A due to finishing at the bottom of the Primera División relegation table. Pachuca Juniors won the right to be promoted to the Primera División A after winning the Segunda División promotional playoff but lacked the certificate of promotion given to teams by the Federación Mexicana de Fútbol Asociación. Instead, Irapuato were promoted to the Primera División A, and two new reserve teams were created for the Indios of Ciudad Juárez (Chihuahua) and Atlante (Chetumal).

Tournament format
A total of 27 teams are divided into three groups of nine teams each. Each team plays the other eight teams in its group twice, once at home and once away, for a total of 16 games. At the end of the regular season the top two teams in each group, as well as the next two highest placed teams, qualify to the Liguilla. The teams are seeded based on their position in the general table and are arranged before each round so that the highest seeded team remaining always plays the lowest seed remaining. The teams play a home and home series and whichever team has the better aggregate score advances. If the two teams are tied after both legs in the quarterfinals and semifinals the higher seed advances automatically. In the finals, if the two teams are tied after both legs two 15 minute halves of extra time are added. If the teams are still tied after extra time the champion is determined through a penalty shootout.

Promotion
One team is promoted to the Primera División each year (two short tournaments). After the Clausura 2009 tournament, the champions of the Apertura 2008 and Clausura 2009 tournaments will play a home and home series to determine which team will be promoted. If the same team wins both tournaments it will be promoted automatically. In order for a team to be promoted it has to obtain a certification from the Federación Mexicana de Fútbol Asociación. If the winner of the promotional final is not certified for promotion a home and home series is played between the highest placed certified team and the club being relegated to the Primera División A to determine which will be in the Primera División.


 * Currently certified teams


 * Atlético Mexiquense
 * Lobos BUAP
 * Cruz Azul Hidalgo
 * Durango
 * Irapuato
 * Mérida
 * León
 * Querétaro
 * Santos Laguna A
 * Dorados de Sinaloa
 * Tijuana
 * Correcaminos
 * Veracruz

Relegation
One team is relegated to the Segunda División each year (two short tournaments). The team that has the worst points to games played ratio over the previous three years (Apertura 2006, Clausura 2007, Apertura 2007, Clausura 2008, Apertura 2008, Clausura 2009) is relegated to the Segunda División.

Torneo Clausura
The Primera División A Clausura 2009 is a Mexican football tournament, the second of two short tournaments held during the 2008–2009 Mexican football season. It began on January 10, 2009, and will run until May 23 or May 24, 2009. The winner of the tournament will earn a place in the promotional playoff against Querétaro, the winners of the Apertura 2008 tournament, to determine which team will be promoted to the Primera División.

Tournament format
A total of 27 teams are divided into three groups of nine teams each. Each team plays the other eight teams in its group twice, once at home and once away, for a total of 16 games. At the end of the regular season the top two teams in each group, as well as the next two highest placed teams, qualify to the Liguilla (playoffs). The teams are seeded based on their position in the general table and are arranged before each round so that the highest seeded team remaining always plays the lowest seed remaining. The teams play a home and away series and whichever team has the better aggregate score advances. If the two teams are tied after both legs in the quarterfinals and semifinals the higher seed advances automatically. In the finals, if the two teams are tied after both legs two 15 minute halves of extra time are added. If the teams are still tied after extra time the champion is determined through a penalty shootout.

Promotion
One team is promoted to the Primera División each year (two short tournaments). After the Clausura 2009 tournament, the champions of the Apertura 2008 and Clausura 2009 tournaments will play a home and home series to determine which team will be promoted. If the same team wins both tournaments it will be promoted automatically. In order for a team to be promoted it has to obtain a certification from the Federación Mexicana de Fútbol Asociación. If the winner of the promotional final is not certified for promotion a home and away series is played between the highest placed certified team and the club being relegated to the Primera División A to determine which will be in the Primera División.


 * Currently certified teams


 * Atlético Mexiquense
 * Lobos BUAP
 * Cruz Azul Hidalgo
 * Durango
 * Irapuato
 * Mérida
 * León
 * Querétaro
 * Santos Laguna A
 * Dorados de Sinaloa
 * Tijuana
 * Correcaminos
 * Veracruz

Relegation
One team is relegated to the Segunda División each year (two short tournaments). The team that has the worst points to games played ratio over the previous three years (Apertura 2006, Clausura 2007, Apertura 2007, Clausura 2008, Apertura 2008, Clausura 2009) is relegated to the Segunda División.