Cochlear implantation is a high cost, low volume intervention which is provided to adults and children with profound hearing impairment. Demand is increasing in the UK as a result of improved technology, changes in intervention criteria and the national newborn hearing screening programme. In order to inform commissioning policy for cochlear implantation in five English primary care trusts, we reviewed the evidence and assessed the complexities of developing needs and of service provision assessment and planning. Our results indicated that the current level of provision was well below what would be expected if the majority of people meeting current criteria were given a cochlear implant. Gaps between the clinical intervention thresholds and the level of service commissioned have widened. Long-term cost effectiveness and incidence studies are needed to assess cochlear implantation in the light of these lower clinical intervention thresholds.