About the document
- Who files:
- A holder of the healthcare right moving to their cover beneficiaries of another holder (children, grandchildren, siblings, wards, foster children)
- Where to submit:
- Social Security e-office, run.gob.es, post or INSS centre (CAISS) by appointment
- Authority:
- Instituto Nacional de la Seguridad Social (INSS)
- Country:
- Spain
- Category:
- Healthcare and health cards
- How to fill:
- Chat in any language → original form → PDF
- Price:
- form free · chat €5 per document
- Last updated:
- Official source:
- https://www.seg-social.es/descarga/es/ASCambiodebenef
What this document is
C-158 (“Cambio de un beneficiario de asistencia sanitaria de un titular a otro”) is an official form of Spain’s National Social Security Institute (INSS). In the Spanish health system a relative can receive care as the beneficiary of a person who holds the right (the titular). C-158 is used when a beneficiary moves from one holder to another — for example, a child registered under one parent who should move to the other parent.
Who files it and where
- the holder of the healthcare right who wants to add as beneficiaries their descendants, siblings, wards or foster children currently registered under another holder;
- it is signed by the person filing: the applicant or a representative (including an attorney in the electronic power-of-attorney register or a person providing support to someone with a disability);
- if the beneficiaries are under 18, the current holder signs section II to consent; without that signature, proof of living together and financial dependence is needed;
- file online at the Social Security e-office (digital certificate or Cl@ve), via run.gob.es, or send a signed copy by post or take it to an INSS centre (CAISS) by appointment.
What the form asks
- section I — applicant: surnames, given name, date of birth, sex, marital status, DNI/NIE/passport, Social Security number, nationality, address, phones, e-mail;
- section II — the holder the beneficiaries are under now: surnames, given name, date of birth, sex, marital status, ID document, Social Security number, nationality;
- section III — up to four beneficiaries: surnames, given name, phone, ID document, Social Security number, date of birth, relationship to the applicant;
- section IV — statements; consent to messages, place and date of signing, INSS province.
What to bring
- the applicant’s ID: Spaniards — DNI; foreigners — TIE or, failing that, passport or national ID card;
- for a son, daughter, grandchild, brother or sister — the family book (libro de familia) or birth certificate;
- for a beneficiary over 26 with a disability of 65 % or more — the disability certificate or card;
- for a beneficiary under 18 without the other holder’s signature — proof of living together and financial dependence (separation or divorce judgment, padrón, etc.);
- for a ward or foster child — the document issued by the competent authority;
- if a representative files — proof of representation.
How to fill it in with FoxDocs
- Tell the chat, in any language, whom you are moving to your cover and from whom.
- The assistant fills the fields in capitals, ticks sex, marital status and consent, and adds the signing date.
- Download the PDF, check it, sign it (and have the other holder sign if the children are under 18) and file it.
Source
Official INSS form C-158 cas V.3 (20241007): seg-social.es — C-158. Checked 2026-10-09. This is not legal advice.