This report quantifies the financial costs and benefits of supporting disabled children and their families. It focuses on two services: short breaks and key workers. The unit cost of short break and key worker services are calculated using evidence from two national surveys. For short breaks, costs are calculated for shared care schemes using volunteer carers. Costs are given per average disabled child. The first step in calculating financial benefits is to identify costs which might be prevented if families had access to services. The second step is to determine the benefits by using a proportion of these preventable costs. These proportions are based on a number of assumptions, all of which are laid out clearly in the text. Benefits are given per average disabled child. For the average child, short break services cost £6,635 per year, or £81,584 over fifteen years. Nearly two thirds of this cost comes from management and overheads. A sober estimate of the financial benefits to society of short break services is £2,505 per year, or £30,737 over 15 years. For the average child, key worker services cost £2,035 per year or £25,023 over 15 years. A sober estimate of the financial benefits to society of a key worker is £1,381 per year, or £16,981 over 15 years. For both short break and key worker services, financial costs are greater than financial benefits. This suggests that the economic case alone is not sufficient to justify investment. But financial savings are just one potential benefit of services for disabled children. There are other non-economic benefits, such as the happiness of the family, which have not been measured.