What are the options for care for very low-functioning autism?

As someone who has been working in this area for nearly 20 years, there are a few things to think about. As others have said, it's important to get the ball rolling on getting things sorted now before your mum's health deteriates, so speak to his GP about a care needs assessment ASAP. Obviously, it's not up to you, but it is worth thinking about whether your brother is likely to inherit anything from your mum when she passes. One option is that she makes out her will so that he doesn't inherit this seems mean but if he has savings he will need to pay for his care needs in full until he has a set amount (used to be £16k). An alternative is that this money be held in trust in such a way as his care is still paid for by the local authority, but he can benefit from the money in other ways. If it hasn't already been done, then your brother will also need to apply for a PIP and income based support if he hasn't already. These things can take time to put in place, and if it's not done before mum passes, then the transition may leave him in genuine want. Obviously, someone will need to do this with or for him. Finally, I wanted to say that while there are horror stories in the news, this is not the norm. They are in the news because they are unusual outliers. The vast majority of adults with learning disabilities and autism are supported in enabling and caring environments. Since the transforming Care Act (2014) came into force, there has been a push away of bigger homes and hospitals into smaller and individual homes. This has come with new models of support around positive person centered support and social normalisation (PBS or positive behavioural support). That's a bunch of buzzwords I know but essentially what it means is that each individual is treated differently to learn new skills and make a positive change in their own lives and giving them the opportunity to have normal social interactions (he doesnt need to be normal only that he can join in the social environment like everyone else). The idea being (and the evidence says it is) that this improves quality of life and minimises behaviours of concern (that your brother may or may not display now or in the future). Good luck and feel free to DM me or reply here and I'll help you out if I can!