Abstract
More than half the world's population has no social protection of any sort. The ILO has started a campaign to remedy this state of affairs, to which this article is a contribution. After first defining the concepts of social security and coverage, the author reviews examples of successful approaches and practices used to extend social security in developing countries, notably low-income countries, for the three main social security programmes: social health insurance, contributory pensions and tax-financed social benefits. Finally, some central policy conclusions and strategies are presented.