Updates of this series will be ceased on December 20, 2019. This series doesn't convey any additional information beyond what's available in the base series published through the H.3 release, BOGMBASE. The discontinued series plotted on the same graph for comparison can be accessed here.
For more details, see the FRED Announcement.
Federal Reserve Bank of St. Louis, St. Louis Adjusted Monetary Base (DISCONTINUED) [AMBNS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/AMBNS, December 4, 2021.