For the purposes of applying for a Visa and or Residency the law requires that you take at a policy that  meets the following requirements below. 

Innoinsure specialise in policies that meet the Spanish Government's requirements and I highly recommend their services:

What insurance is required for the Visa or residency application

Based on the Organic Law 4/2000 ( by Royal Decree 557/2011) and the Law 14/2013 ( September 2013), the Spanish embassies and Ministry of Foreign Affairs requires that, to apply for one of the followings:

1. Student Visa
2. Investment Visa (Golden Visa)
3. Non-lucrative Visa
4. TIE card (the residence permit)
5. Renewal of TIE card

Medical insurance with the following features needs to be presented:

1. Operates in Spain
2. Full coverage, including emergencies, consultations, diagnostic tests, surgeries (inpatient and outpatient), and hospitalizations, etc
3. Unlimited financial coverage
4. No co-payments or deductibles
5. No waiting periods
6. Repatriation of remains
7. Coverage is required for the entire stay that the applicant will be in Spain.