The State System
Spanish state health insurance fund is known as the Instituto Nacional de Gestión Sanitaria (Insalud).  Employers must register their employees with the social security fund known as the Seguridad Social when a new employee starts work. Once registered you will receive a registration card known as a cartilla de la seguridad social or a tarjeta sanitaria. It will either be posted to you or you may have to collect your card from your local Centro de Salud. Dependant family members are covered by the contributions of the working family member and will share the same social security number. Employees and employers pay a percentage of their wages into the Seguridad Social; how much is dependant on what you earn, but employees pay 25% of the fee and employers 75%. All other people must register at the Nacional de la Seguridad Social (NSS), where they will be given a social security card with a social security number on it. When you receive your social security card you are can to register with the nearest public health centre and receive free public healthcare. The unemployed, old age pensioners and people on long-term sickness benefit or maternity leave do not have to pay healthcare contributions, but must register with the NSS to qualify.

Foreigners from outside of the EU who are immigrating to Spain without jobs must produce proof of private health insurance in order to obtain their residence permit, foreigners will be entitled to free health care once they have been employed and paying their contributions for two years continuously. 

People immigrating to Spain from the EU who are not working need to produce for E106 to the NSS. Pensioners from other EU member states must provide the NSS with form E121, available from their home countries social security office. All citizens from EU states wishing to live in Spain must go to the NSS and show their passport, birth certificate, appropriate E form, marriage certificate and proof of residence in Spain.