Maintaining contact with services will help improve clinical and social outcomes as children with epilepsy move into their adult lives. This study has collated evidence on the extent to which young adults with epilepsy are supported by health and social care services posttransition, and the costs of such support. UK prevalence and service use data were taken from policy and research literature, as well as national data sets and reports. Costs were attached to these data to arrive at agency and overall total costs. There are approximately 42,000 young adults (18-25 years) with epilepsy costing the UK health and social care budgets 715.3 pound million per annum, on average 17,000 found per young adult with epilepsy. A further 61 pound million falls to the social security budget. Most young adults with epilepsy will rarely use these services, but those with additional health needs have high and often long-term support needs, including supported accommodation and personal care. Current resources used by these young adults are summarised but deficits in service availability can mean long waiting times and sub-optimal treatment. Young adults also want more support to help them take advantage of education and employment opportunities and more information about managing the impacts of epilepsy on their lives. Improving services will cost money, but has the potential to lead to better outcomes for young adults.