Cash transfers for the elderly with little or no link to previous contribution, or work history are employed in many countries to provide income support for the elderly. In the context of the larger debate over pension reform, some argue that these 'social pensions' are an effective way to deal with chronically low coverage of contributory schemes, and to alleviate poverty among the elderly. This paper reviews the global experience with social pensions. We find that coverage and cost of these programs varies widely, and that the appropriate role for social pensions should take into account several country-specific conditions. The extent of coverage of the contributory scheme, the extent of other social assistance programs, and the relative poverty status of the elderly are among the factors that should be considered. Design and implementation issues will be reviewed in Part II.