Social protection systems have to cope with large discrepancies between the financing needed to cover demand and the resources actually available. For this reason, it is necessary for any reform proposal to include elements of cost restraint as well as measures to increase the population coverage of systems. Efficiency and solidarity must improve together if progress is to be made towards universality of benefits. Any reform strategy needs to consider not only the financial constraints imposed by the macroeconomy, but also the heavy drain on financial resources and the effects on the fiscal accounts that may result from whatever scheme is chosen owing to the amount and volume of benefits, the limited scope for funding them out of contributions, and the need for redistributive financing. This article looks at various approaches to social security finance reform, involving new and different public-private mixes.