This paper investigates the effects on labour supply, consumption and savings of a change in the superannuation tax structure, involving the taxation of contributions to a fund, pre-retirement earnings of the fund, and the benefits received from the fund during retirement. The effects on lifetime plans of tax changes are investigated using a simple three-period model in which the final period is retirement. The effects of unanticipated changes, requiring revisions to plans, are examined. Although the partial effects of particular tax changes are unambiguous, the effects of allowing for a government budget constraint mean that it is difficult to predict a priori how labour supply is likely to be affected. However, private savings unambiguously fall.