Article 20 4.

If the members of the family of an insured person reside in a Member State other than the Member State in which the insured person resides, and this Member State has opted for reimbursement on the basis of fixed amounts, the cost of the benefits in kind referred to in paragraph 2 shall be borne by the institution of the place of residence of the members of the family. In this case, for the purposes of paragraph 1, the institution of the place of residence of the members of the family shall be considered to be the competent institution.