This document describes the concepts, data and methods used in the 2019 report (under Article 17 of the Habitats Directive) on the conservation status of habitat types for the parameters range, area, structure and functions, and future prospects. The ranges of nearly all habitat types have not changed. No reliable, updated data on area were available for most habitat types. The methodology for assessing structure and functions has been thoroughly revised to accommodate long-term monitoring data and meet the new reporting formats. The European Commission has also introduced a new method for assessing future prospects. The report presents the results and indicates where the methods and data can be improved.