The EHIC European Health Insurance Card (in Portugal Cartão Europeu de Seguro de Doença - CESD) only covers unplanned medical expenses and is not travel insurance.
The EHIC (in Portugal CESD) allows all legal European residents, who have their countries social security coverage, to benefit from emergency medical treatment and care when temporarily abroad, within Europe.
If you move from the UK and take up residence in Portugal, before retirement age, then you should apply for a CESD to cover you when you travel outside Portugal. However the Portuguese authorities are only issuing new cards when your UK one expires, they seem content to charge the UK for any medical expenses British residents have until their UK EHIC runs out. If you are below retirement age then when your UK EHIC runs out you will need to get a Social Security number to continue your subsidised access to the Portuguese health system. You can then also apply for a Portuguese CESD.
If you are still a UK resident for retirement purposes or because you still spend most of your time in the UK then you need to renew your EHIC in the UK and you will need to inform your Centro de Saúde of your new EHIC number. This also applies to visitors from other EU countries, you will apply for a renewal in your home country.
From 01 May 2010, the responsibility of issuing the EHIC changed from the persons state of residence to the state where the person is paying in to or getting benefit from the Social Security System. This affects people receiving state pensions or other benefits from their home country and not their country of residence. Therefore a retired person from UK living in Portugal will now apply for their EHIC from the UK. For further information visit the UK NHS website.
Applying for an EHIC/CESD in Portugal
Application can be made at the local social security office (Centro de Segurança Social), or at the nearest Citizen's Shop (Loja do Cidadão).
Portuguese residents using a CESD when visiting another EU country need to make sure the card is valid. It is valid for up to three years and each member of a family including children, must have their own card.