Description: Development of annuities markets is a critical element of any private system. In Mexico, when the new pension regimen came into existence in 1997, the Mexican Institute of Social Security [IMSS] was supposed to buy a single premium annuity for all the people who become eligible under the new regime. Disability pensions represent 37% of total pensions sold up to date. Mortality of disables show substantial differences against the mortality table use to compute the annuity. Most of the differences can be explained by looking at the disability causes. Using information for social security for 2001 and 2002, regarding mortality and disability, this is the abstract of a paper that presents the main causes of disability among disables and the main causes of mortality of those disables who died in their first and second year of disability. The analysis of those cases apart from explaining the important differences between the expected mortality and the observed mortality during the first two years of disability, also explains some of the latter changes in the operational rules of IMSS.