Residential treatment is one of a number of treatment modalities for drug misuse. Before a drug user receives national health service care in a residential drug treatment service, care planning needs to be undertaken between the service user and their clinicians to assess whether it will help the user to change their behaviour and if so, the nature and duration of the treatment that will be needed. They will also consider the care that will be needed following residential treatment. Without such assessments it is not possible to estimate the cost of placing all problem drug users in residential treatment.