Primera División "A" de México (1994–2009) In 1994, the
FMF created the Primera División "A" as an intermediate league between the
Primera División and
Segunda División, to try to reduce the gap between the clubs in the top division and the lower divisions. The project was under the direction of José Antonio García Rodríguez, then president of the Primera División. He envisioned the new division to be joined by the best clubs of the Segunda División and include clubs from the United States,
Los Angeles Salsa and
San Jose Black Hawks expressed a desire to join. FIFA declined the integration but established a new league with the best Segunda División sides. The inaugural season had fifteen founding clubs:
Atlético San Francisco,
Atlético Yucatán,
Caimanes de Tabasco,
Celaya,
Gallos Blancos UAQ,
Gallos de Aguascalientes,
Guerreros de Acapulco,
Irapuato,
La Piedad,
Marte,
Pachuca,
San Luis,
Tepic,
Tijuana Stars and
Zacatepec. In 2006, the number of clubs increased from 20 to 24, and geographically separated into two groups (A and B).
Liga de Ascenso de México (2009–2012) In 2009, the division was renamed as Liga de Ascenso de México. The league was reduced to 17 clubs and the groups were eliminated in the regular phase. The
Apertura 2010 had 18 participating clubs, the league was rebranded in 2012. In 2013,
Alebrijes de Oaxaca was the 16th club to join Ascenso MX, Alebrijes was partly formed by consolidating Segunda División side Tecamachalco which had won promotion to Ascenso MX in 2012, but did not fulfill infrastructural requirements set by the Mexican Football Federation. In August 2013,
Zacatepec was promoted to Ascenso MX in place of relegated
Pumas Morelos. From 2011 to 2016, there was no relegation to Segunda División. On June 6, 2016, returned the relegation for the 2016–17 season.
Loros UdeC and
Murciélagos were relegated in the next two seasons. In 2018–19 season,
Tampico Madero finished last in the relegation table, but remained in Ascenso MX after paying a bail.
Ascenso MX (2012–2020) In 2012, the league rebranded its name, logo and competition format as Ascenso MX, the clubs do not need the FMF certification to be promoted and the division no longer used format with groups in regular phase. On 13 April 2020, Liga MX and Ascenso MX President Enrique Bonilla announced the termination of the remainder of the Clausura 2020 season. Two reasons were the
2019–20 coronavirus pandemic and the league's lack of financial resources. The Ascenso MX was replaced by the
Liga de Expansión MX on 17 April 2020. ==Stadiums and locations==