ALEXANDER reports a study on TSO-DSO coordination schemes for procurement and activation of flexibility across transmission and distribution grids in this deliverable. The study focuses on conceptual and quantitative analysis of different possible coordination schemes, grouped into four clusters, namely (i) TSO-only procurement cluster, (ii) TSO-DSO separate procurement cluster, (iii) TSO-DSO joint procurement cluster, and (iv) Combination of explicit and implicit mechanism cluster. The relevance of these coordination schemes to the Belgian context is also analyzed. Furthermore, key action points for setting up each cluster are formulated. This work has been presented in an ALEXANDER workshop that involved four DSOs (Fluvius, ORES, RESA, and Sibelga), which are the members of our sounding board. The slide deck of this workshop can be found here.