Through Deliverable 3.1 “Outcomes of the gap analysis of large medical cohorts,” we have established a formal definition of LMedC and mapped the current European landscape of cohorts and research infrastructures. A Delphi study identified key gaps in depression, Alzheimer’s disease and other dementias, and endometriosis, while a scoping review highlighted existing cohorts in these areas. Experts pointed to lack of data quality, comparability, and reluctance to share data as major barriers, recommending the creation of a dedicated research infrastructure. In WP4, we mapped available infrastructure services across the research-data lifecycle, based on surveys and interviews with 25 organisations, revealing strong capacities in areas such as data services, biobanking, and ethics, but also a fragmented landscape with limited full-spectrum coverage. This work informs coordination, scaling of services, and EU investment, and contributes directly to policy discussions on the EHDS, EOSC, and ESFRI roadmaps. Deliverable 6.1 introduced guidelines for assessing LMedC suitability for inclusion in future infrastructures, considering ELSI and FAIR principles, while Deliverable 6.2 reviewed strategies for engaging participants, researchers, and cohort managers, offering recommendations on incentives and stakeholder involvement. Deliverable 9.1 analysed stewardship and data sharing models, mapping ethical, legal, and IT requirements and recommending specific technologies for data discovery (BBMRI-ERIC directory/locator, DataShield), access negotiation (BBMRI-ERIC negotiator), and analysis (DataShield), to be further developed in connection with EOSC and EHDS. Finally, Deliverable 11.1 presented the first version of the clinical cohort catalogue, populated with 68 cohorts from UMCG, and defined next steps for expanding its scope and improving the underlying software.