Nowadays, we are witnessing a wide and spread need to create flexible retirement schemes for facing global ageing and the prolonging working lives. Many countries have set up Social Security Systems, which link retirement age and/or pension benefits to life expectancy. In this context, we consider an indexing mechanism based on the expected residual life expectancy to adjust the retirement age and keep a constant Expected Pension Period Duration (EPPD). The analysis assesses the impact of different stochastic mortality models on the indexation by forecasting mortality paths based on extrapolative methods. Nevertheless, so far, in recent literature less attention has been given to the uncertainty issue related to model selection, although ha...