The current information from www.nhs.uk/NHSEngland/Healthcareabroad/m...es/Introduction.aspx is that you do need an S1 (see below). And indeed I have recently arranged for one to be sent here.

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If you are living in an EEA country or Switzerland and you receive a UK State Pension or long-term Incapacity Benefit, you may be entitled to state healthcare paid for by the UK. You'll need to apply for a certificate of entitlement also known as an S1 form. If you are living in Iceland, Liechtenstein, Norway or Switzerland then the form is called E121.
You can apply for your form via the International Pension Centre on 0191 218 7777. Once issued, register the S1/E121 form with the relevant authority abroad. Often you need to do this before you can register with a GP surgery or obtain a medical card.
Once you have registered your S1/E121 in the country you are moving to, you will be entitled to apply for and use a UK-issued EHIC to access state-funded necessary medical treatment when you visit other EEA countries.

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