All departments, agencies and hierarchical information represents the complete data series available from federalregister.gov (last updated on April 8, 2014). In the future, we hope to improve the hierarchical information by combining the data set with information from authoritative sources and also include budget information. At such time, this notice will be updated (including sources).
As of now, smaller departments available in the 'alphabetical' listing are not necessarily available in the 'top-down hierarchy'. As always, suggestions and help with improving data sets, especially those related to government transparency is greatly appreciated.