Description: Mexico substituted its defined benefit system [IMSS] of the formal sector by a defined contribution system in 1997. The initial plan called for buying single premium annuities for the widows and disabled workers under the new system. In the first three years, this market came to occupy a significant part of the insurance sector. Then, the number of workers getting benefits started to fall dramatically. This is the abstract of a paper that shows that such a fall has been a direct result of how the IMSS authorizes the issuance of single premium annuities. The paper analyses the rationale behind such a dramatic change in policy, analyzes various possible scenarios of IMSS strategies, and examines the problem to see if it brings in any long-term benefits to IMSS.