The article takes a brief tour of the historic Mexican government since the sixteenth to the twenty first century, to describe the process of institutional change in government in Mexico through two mechanisms: the reform and administrative modernization. The institutional transformation via the reform starts with the Bourbon reform in the viceregal era, to transit in Independent Mexico towards the seven most important administrative reforms: the 1833, the creation of the Secretariat Building (1853), Juarez reform (1857), changes after the revolution (19 10), those which correspond to the period 1917 to 1970, the administrative reform (1970-1976) and the reform of the 1976-1982 period. It also examines the institutional transformation via the modernization programs: decentralization, simplification, administrative modernization, fighting corruption and promoting transparency, and improvement of management. From the new institutional framework is based on the premise of North (1995), in the sense that the "institutional change shapes the way in which societies evolve over time, making it the key to understand the historical change" (North, 1995, 3). This idea is applied to public administration in Mexico to argue that, in addition to the stages of institutional reform and modernization, the issuance of the Federal Law of Transparency and Access to Public Information (2003), which gives rise to the Federal Institute of Access to Information Government (2002), the launch of the service career (2003) and the creation of the Ministry of Public Administration (2003), are events that are intended to achieve an institutional change in the government apparatus in an incremental way.