Mexico’s Constitution provides the legal and political bases for immigration policies. Article 30 enumerates the two types of Mexican nationals: those by birth and those by naturalization. Mexico’s immigration law is detailed in the General Population Act (GPA). The GPA and its regulations represent the most important federal legislation regarding immigration and closely parallels the U.S. Immigration Act and Regulations. However, the GPA is comparably simplistic and not as technical due to the fact that Mexico, unlike the United States, is not a country of immigrants, and this was reflected in its immigration laws. As in the U.S., other Mexican federal statutes also apply to foreigners and their activities while in Mexico.

Individuals seeking entry to Mexico are divided into two categories by the GPA: (1) a Non-immigrant is admitted to Mexico temporarily under one of eleven categories. Each category contains provision on length of stay, renewal, etc. (2) An Immigrant is admitted to Mexico, under one of nine categories, with the purpose of residing there to attain the status of Inmigrado (lawful permanent resident), in accordance with Article 44 of the GPA. To attain inmigrado status, immigrants must remain in Mexico for five consecutive years as well as comply with various other strict requirements, depending on the category (Article 52, GPA). Interestingly, in 1998, amendments to the Mexican Constitution will allow the possibility of dual nationality for Mexicans in specific circumstances.

As a result of the November 8, 1996 revisions to the GPA, two unprecedented chapters were added, establishing some basic rules on immigration procedure: one on immigration questions (Chap. IX) and the other on verification and compliance (Chap. X). It is hoped that this constructive development will lead into a clearer recognition of the rights of aliens, both substantive and procedural.