This article takes a long-view of the huge rise in disability claimant numbers in the UK since the early 1980s and looks ahead to the trends that can now be expected to emerge in an era of fiscal austerity and welfare reform. The article's central thesis is that disability numbers are best understood as part of a triangular relationship between levels of employment, unemployment and sickness. In particular, the big decline of industrial employment in many places has often resulted in large-scale ‘hidden unemployment’ on disability benefits, especially among low-skilled workers. Looking ahead, the UK's welfare reforms are set to reduce disability claimant numbers but principally by restricting access to Employment and Support Allowance, the new disability benefit. The main effect will be to divert substantial numbers of men and women with ill health or disability onto unemployment benefits instead or, more often, out of the benefits system altogether.