Earlier papers in this series on the IMF examined the extent of continuity and change in the content of the IMF's programmes and evidence on their effects. This paper concludes the series by surveying some unresolved issues concerning the design of these programmes. The paper begins with a brief exposition of the basic policy model used by the Fund. The bulk of the paper is then taken up with discussion of issues arising: concerning the limitations of the model; the policy instruments and performance criteria employed in the programmes; the problem of programme inflexibility; and the difficulties the Fund has in handling the political aspects of stabilisation policy. Part III of the paper pulls the discussion together and suggests improvements in programme design.