If you’re in the UK
If you give up your home to go and live with an elderly parent you could be made homeless if they have to go into a care or nursing home. If you’re under 60, not disabled and not terminally ill then the local authority has no obligation to let you remain in the property. If you’re over 60, terminally ill or disabled then they can either put a charge on the house or disregard the house. A charge on the house only buys you time – once your parent dies then you have a mere six weeks to repay the money to the local authority. Failure to do so results in interest charges. Clearly if you need to sell the property to repay the money n way are you going to get probate and sell a house in 6 weeks. The minimum will be more like 6 months.
If you move in with a parent get them to make you a tenant in common. Provided this is done at least 7 years before they need to go into a care or nursing home then the local authority has to disregard the house when calculating the contribution that your parent would have to make towards the cost of their care.
If your parent is unwilling to name you on the deeds of the house – perhaps because you have siblings and the property is left to all of you in a will ensure that you have a letter signed by the person you care for – and witnessed – giving you right of abode for their lifetime. Failing to do this could result in you being made homeless with the consequent emotional and financial consequences.