This document has been taken from the Richmond Gov website and quite clearly lays out the conditions that have to be met for a young person to be eligible for adult social care services.
This resource is a guide to the Care Act with the full title of: 'How to get the right support from your local authority'. It is one of several useful guides produced by hft. hft is a long established charity supporting people with learning disabilities. They provide resources, such as this guide, and a range of services.