The reform of the pension system is topical again. It is also nothing new. Since practically the mid-1980s, Spain has undergone a sustained process of reform of its pension system. The objectives of the reforms have been diverse: expand and improve coverage of social protection, modernize and rationalize the financial structure of the system and guarantee its sustainability in the face of demographic challenges. And it is that the combination of low fertility rates since the second half of the 70s, increased life expectancy and the onset of the boomers’ retirement have an impact on public spending of colossal magnitude.