Actuaries play a key role in the design, implementation and operation of social security schemes. Their expertise is an important contribution to the decision-making process in this respect. Actuaries should be aware that their involvement will include areas with often conflicting objectives, and they will need to use their judgement in the formulation of recommendations. The areas of input are likely to include the costing of new schemes, funding, financing and sustainability considerations, as well as considerations of adequacy and coverage.