This previous Penal Code from 1872 was replaced in 1929. The new legal order aimed to modify the legal architecture of the Porfirio Díaz dictatorship, which was based on penal repression, to align it with the context of the constitutional guarantees and social justice proclaimed by the Mexican Revolution of 1910.

Once again, any notion of homosexuality (both male and female) was formally excluded from the document. The potential criminalization allowed by the previous code due to the vagueness of the sanctions related to 'offenses against public morality and good customs' is now technically limited solely to a prohibition of pornography. Thus, Article 536 536 (Second Book; Title 8 'Crimes against Public Morality'; Chapter I 'Offenses against Public Morality or Good Customs') mentions imprisonment and fines for those who reproduce or manufacture obscene writings, images, or objects, as well as for those who display or commercialize such obscene expressions in public.

Again, in 1931, the penal code was substituted by the one that still governs at the federal level today. However, in 1966, Article 201 (Third Book; Title 8 'Crimes against Public Morality and Good Customs'; Chapter II 'Corruption of Minors') was reformed, and for the first time, a reference to homosexuality appeared. It established imprisonment for anyone who induces or incites a minor under 18 years old to engage in 'homosexual practices.' The penalty was doubled if the act was repeated and resulted in the minor 'acquiring habits of homosexual practices.'

Finally, those last provisions that indirectly incited the criminalization of homosexuality were eliminated in the 1999 reform.

Since 2003, the Federal Law to Prevent and Eliminate Discrimination has defined in Article 9, sections III and IV, the following as acts of negative discrimination:
• Prohibiting the free choice of employment or restricting opportunities for access, retention, and promotion within it.
• Creating differences in wages, benefits, and working conditions for equal work.
This is directly related to sexual orientation, as the former Article 4 of this law (renumbered as Article 1, section III after the 2022 reform) explicitly includes it as a basis for potential discrimination.

Subsequently, in 2014, section V was added to the same Article 9, stating that creating differences in wages, benefits, and working conditions for equal work is also considered another act of negative discrimination.

In 2012, Article 2 of the Mexican Federal Labour Law was amended to explicitly include sexual orientation in the list of factors for which employers, both public and private, must not discriminate against their workers. This reform aimed to foster dignified working environments that uphold human dignity.
Similarly, Article 3 was also revised to state that work is a right and a social responsibility; it is not a commodity. Therefore, no discriminatory practices based on workers' sexual orientation may be allowed.
Likewise, since then, Article 56 has stipulated that working conditions may never be less favourable than those established by the Law and must be proportional to the importance of the services provided and equal for equal work, with no differences or exclusions based on sexual orientation.

Article 1(3) of the Federal Act to Prevent and Eliminate Discrimination (2003) includes “sexual preferences” as one of the prohibited grounds of discrimination. This law applies to housing as per Article 9(XXI). Gender identity is not explicitly mentioned

NOM 253 removes targeted restrictions on blood donations from gay and bisexual men. Instead, it prohibits donations from individuals with HIV or hepatitis, their partners, and those who participate in "high-risk sexual practices," irrespective of their sexual orientation.