With the Connecting Europe Facility (CEF) programme coming to an end in 2020, the question of the long-term sustainability of the CEF-funded Digital Service Infrastructures (DSIs) beyond the programme needs to be addressed. The objective of this study was to assist policy makers in selecting the most relevant and credible solutions to ensure the sustainability of all DSIs post-2020. The assignment therefore focused on identifying the long-term needs and requirements of each DSI and across DSIs. It established a list of possible solutions and assessed those from an individual and cross-DSI perspective and according to the characteristics of groups of DSIs, by means of a sensitivity analysis. All these steps were also summed up into a Pugh analysis comparing the benefits and weaknesses of the most promising solutions in order to provide policy makers with a menu of options for the future. It emerged that handover of DSIs to an EU Regulatory Agency would be the most suitable solution taking all DSIs together, but that inclusion in a new programme to take over from the CEF from 2021 would also be a very viable option. The study also explains which solutions could suit individual DSIs or clusters of DSIs best