Among 1+MG signatory countries, it is agreed to collectively develop a cohort of at least one million European citizens that have their genome determined via Whole Genome Sequencing (WGS). The goal is to make the personal genomic data and associated health information accessible in a secure manner for the different purposes in health care (prevention, diagnostics and therapy), research and innovation, and public health. To achieve this goal, the Beyond 1 Million Genomes Project (B1MG), will provide a set of recommendations for the long-term sustainability of the initiative beyond the B1MG including guidance for countries on how to establish funding routes to ensure the establishment and maintenance of the infrastructure to enable federated cross-border access to genomic and associated phenotypic data in the long term. Long-term sustainability of the 1+MG initiative will require an appropriate organisational structure and plan. The Governing Board of B1MG will be crucial to this aim. Potential legal and financial frameworks for developing the initiative at national and international level will be explored together with its insertion/ institution as a major contributor to future initiatives. Sustainability is built on the basis of four dimensions that we will have to consider beyond the proyect and beyond this task. This four dimensions are: Financial dimension: how the initiative will be financed at European, national, local and user level. Legal dimension: how the initiative will be used in compliance with legal and data protection standards. Governance dimension: in terms of Member States involvement and legal standing of the coordination entity for cooperation of Member States. Data access dimension: related with the governance of the data and the liability of data protection. Also, particularly important, is that the initiative should work on establishing a training and education plan on e-skills for students and healthcare professionals, hospital managers and policy makers to be put in place at the same time as the infrastructure and technologies for data exchange are put in place within healthcare systems. This Policy Brief is a first document (of three) that focuses on the dimensions of financial and legal aspects of sustainability and has been elaborated with main conclusions drawn from the first policy and legal context and mapping analysis.