Natalie,
When you move to Spain and become a fully registered resident you and your family will fall into different categories depending on whether you are working or not? I'm presuming that you will be both under 65 when you emigrate?
Let say your husband starts work as an employed person: His tax and ni contributions paid from his salary should cover him for the cost of his healthcare as it would in the UK and he would be treated like any Spanish citizen.
If you decide not to work then you should also be exempt from paying NI contributions as long has you have been making NI contibutions for 3 full years into the UK National Insurance system prior to the year you move to Spain.
Any child under 18 in full time education or not registered for work should also qualify for free healthcare.
Approx 4 weeks before leaving the UK to live in SPAIN YOU MUST CONTACT the Overseas Division for Medical Benefits Tel: 0191 218 1999. They will check your NI records to confirm your status for receiving a E106 certificate(they will send you 2 copies) that you can hand over to the medical authorities when you arrive in Spain. The Spanish equivalent of the DSS will then be able to use this certificate to reclaim the cost of providing you with free medical treatment from the UK authorities.
Incidently,if only you or your partner has paid into the Uk NI system for 3 years and neither of you are initially working in Spain then you would both qualify for free public healthcare. The DSS system in the UK allows for one partner to be DEPENDANT on the other! BUT again you must apply for this status prior to leaving the UK.
Finally! Once you have declared that you will be resident in Spain you will no longer Qualify for Free Medical Treatment in the UK unless you are a visitor requiring Emergency treatments!! Should you move back to the Uk on a permanent basis then you have to apply to be readmitted into the UK system!
You can also call the Dept of Health on 0113 254 6334 who should advise you of what medical treatments you may receive free of charge in Spain?
Hope it was of some help?
Mike T