Advances in medical genetics and personalized medicine make Genetic Counseling (GC) essential. As the burden on genetics professionals increases, strategies to strengthen these services are urgently needed. Mentorship in GC (MGC) is a service implemented in some countries that promotes the safe practice of genetics professionals, preventing burnout and preparing them to face new challenges, in a process of continuous competence improvement and ensuring greater patient satisfaction with their healthcare. However, MGC services differ from country to country, ranging from lack of awareness to mandatory practice as a way to respect the patient’s right to excellent care. This inequality originates from the asymmetric development of the GC profession worldwide. Spain, France, and Portugal have specialized training in this field, but have not yet achieved recognition of this profession. Therefore, they have a very small and dispersed number of professionals, lack mentorship services, and do not have a joint strategy for their development. All this context justifies cross-border collaboration to address this shortcoming. MAG-SUDOE proposes a pioneering solution to jointly implement an MGC service in the SUDOE that will benefit the three involved countries. The project will promote the resilience of genetic services and the improvement of the knowledge and resources of their professionals through training activities inherent to 1) the transfer of competencies from the Portuguese pilot action to evaluate the feasibility of an MGC program; 2) the joint development of MGC methodologies; and 3) the design of a joint strategy for its implementation. It will leverage synergies between genetic counseling professional associations and leading biomedical institutions in healthcare innovation. The results will offer a starting point to promote genetic counseling on a transnational scale, creating evidence that will inform health policy decisions for an egalitarian and quality healthcare system.