The doctor practising as a replacement or the student fulfilling the conditions laid down in article L. 4131-2 undertakes, for the duration of the contract, to carry out a replacement activity in one or more medical practices located in the areas defined in article R. 1435-9-1. If, during the term of the contract, he decides to set up a private practice or to work there as a private practice collaborator, the replacement doctor or the student who has signed the contract may request that the benefit of the contract be maintained until it expires. In this case, they may be eligible for the aid provided for in the contract in proportion to the time remaining. In this case, an amendment to the contract is concluded.