This article assesses the challenge posed by the access to a pension for the least educated and more vulnerable Colombians.It relates the trends of the labor market with the low pension coverage: the bias of the urban modern employment against the least educated workers has generated a life cycle in the labor market (salaried employment for the young persons, informal employment for the adults): during his wage-earning early phase they perceive higher earnings, except in the periods of unemployment, and contribute more to the pension system; during his mature phase as informal workers they perceive lower income and stop contributing.Coupled with the very low quality of the rural employment, it explains the low pension coverage of the national population.We model the future labor market performance and pension contributions of a sample of 167,304 individuals in working ages in the third quarter of 2007 DANE´s national households survey.We estimated their survival rates until they are 65 years old, their annual probabilities of transition between wage earning, self-employment, unemployment and inactivity; for single ages, gender and education level; we estimate also, the number of weeks and monetary contributions by each individual.The results show that an important share of the most educated will be able to comply with the requirements to obtain a pension, while most of the least educated not.To increase the share of pensioned workers, we have considered a series of modifications to the Colombian labor market, and assessed also the effects of the "familiar pension".We show that pension coverage does not increase much under the individual capitalization regime, nor under the pay-as-you go regime (unless it experiences important actuarial deficits).Even when the density of contributions significantly increases, and the wages of salaried workers increase when employment among wage earners is formalized, the share of workers accessing a pension is still small given the very low income of the informal workers.Nonetheless, excluding the minimum pension guarantee, under the individual capitalization regime, the most optimistic scenario (which includes an increase of 50 percent in the share of educated workers) substantially improves the global pension coverage.This becomes possible by guaranteeing the population high wages and contribution densities.Finally, we assess the impacts of the economic periodic benefits (BEPS) on the pension possibilities of the least educated population.