The following are Subsidiary Members of the CHIS:

• Any family member (as defined in Article S IV 1.02 of the Staff Regulations and Rules) of a Compulsory Main Member;
• Any family member of a Post-Compulsory Main Member;
• Any family member of a Voluntary Main Member with a normal health insurance.

The membership of Subsidiary Members who meet the above criteria is compulsory and automatic.

For spouses who have no other health insurance, the CHIS will function as their primary health insurance (basic health insurance) and a monthly additional contribution is payable according to their gross monthly income deriving from a professional activity and/or of any retirement pension received by the spouse.

For spouses who have their own health insurance recognised by CERN as a similar health insurance in accordance with the CHIS Rules, e.g. the French Sécurité Sociale or a Swiss LAMal insurance, the CHIS will function as a supplementary health insurance without supplemental contribution.
A proof of health coverage will be requested. For the LAMal, your spouse's insurance will provide it upon request. For Social Security in France, an "attestation de droits" can be downloaded from the health insurance website ameli.fr. 

In order to keep the health insurance cover of their family members up to date, Main Members are obliged to declare in writing to Organization any change in family status or any change in the spouse's gross income.