As a general rule, in the EU/EEA, you are covered by the social security system of the country that is paying your pension. Therefore, in the EU/EEA, the country that is paying your pension is responsible for your (and your family members’) health coverage.
If you move to an EU/EEA country temporarily, then, by presenting your EHIC, you will be able to access medically necessary state-provided healthcare on the same terms and at the same price as locals in the country of your stay.
If you move to an EU/EEA country permanently, request an S1 form in the country that is paying your pension (and that is thus responsible for your healthcare), and register it in the country where you have permanently moved.
In that way, you and your family members will have full access to the healthcare system of your new country of residence.
What if I receive a pension from more than one country?
If you receive your pension from more than one country and one of those countries is the country where you live, then the country where you live is responsible for your health coverage, as well as the health coverage of your family members.