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.

In December 2009, Mexico City approved the recognition of same-sex marriage with it taking effect in March 2010, becoming the first region of Mexico to recognise such.

In Mexico City, there are no laws restricting the discussion or promotion of LGBTQ+ topics since the removal of homosexuality from Mexico's federal "corruption of minors" law.

In 2015, Mexico City provided legal gender recognition on the basis of self-identification after removing the surgery requirement. Since 2021, this is also provided for minors as young as 12.

There are no government restrictions placed on gender-affirming care and government guidelines for public health institutions endorse medical intervention with transgender youth. However availability proves a problem in many areas.

Since 2025, Mexico City provides legal gender recognition for nonbinary and intersex people.

Since 1917, Article 1 of the Political Constitution of the United Mexican States has prohibited discrimination on any grounds. However, the explicit mention of sexual orientation as a basis for discrimination was only added during the 2011 reform of this article. Since then, it has also established that all Mexican authorities, within their respective jurisdictions, are obligated to promote, respect, protect, and guarantee human rights, in accordance with the principles of universality, interdependence, indivisibility, and progressiveness. Consequently, the Mexican State must prevent, investigate, sanction, and remedy human rights violations. Provisions related to human rights must be interpreted in accordance with the Constitution and international treaties, always favouring the broadest protection for individuals.

Before this, in 2003, the Federal Law to Prevent and Eliminate Discrimination was enacted, marking the first legal tool requiring the Mexican State to create the conditions necessary for the real and effective equality of individuals. As a result, federal authorities must take action, both independently and collaboratively, to remove obstacles that hinder or prevent the full development of individuals and ensure that everyone enjoys the rights and freedoms guaranteed by the Political Constitution of the United Mexican States and by international treaties to which Mexico is a party. And thus, Article 4 (now Article 1, section III after the 2014 reform) of this law explicitly includes sexual orientation as one of the grounds for negative discrimination.

Also, 3 out of 32 subnational jurisdictions bans discrimination based on gender identity in its State Constitutions.

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

In 2010, a legislation passed in 2009 in Mexico City to allow same-sex couples to adopt took effect. This would be the first region of Mexico to allow such adoptions.

There is no ban on intersex infant surgery in Mexico, and they are reportedly commonplace.

Since 2012, LGBTIQ+ people are permitted to serve openly in the Mexican military.

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.

In 2020, Mexico City approved a bill banning conversion therapy, becoming the first area of Mexico to do so.

Illegal with a minor under 12, ambiguous rulings observed 12-18, universally legal 18+.