Entitlement to access free national health service hospital treatment is based on whether someone is ordinarily resident in this country, not on British nationality or the past or present payment of National Insurance contributions or United Kingdom taxes. Anyone who is not ordinarily resident is subject to the National Health Service (Charges to Overseas Visitors) Regulations 1989, as amended. These regulations place a responsibility on NHS hospitals to establish whether a person is ordinarily resident, or exempt from charges under one of a number of exemption categories, or liable for charges.
Anyone who lives outside this country for more than 6 months is no longer automatically entitled to free NHS hospital treatment as they will not be considered ordinarily resident here. They will therefore be liable to charges unless they return to the UK to resume their permanent residency, or if they are exempt under another exemption category.
Successive Governments have not required the NHS to provide statistics on the number of overseas visitors seen or treated under the provisions of these regulations or on the costs of treatment. It is therefore not possible to provide the information requested.