Updates of this series will be ceased on December 20, 2019. Interested users can construct a proxy of the difference between monetary base from the H.3 release and currency component of M1 from the H.6 release. The discontinued series plotted on the same graph with the calculated data can be accessed for comparison here.
For more details, see the FRED Announcement.
Federal Reserve Bank of St. Louis, St. Louis Adjusted Reserves (DISCONTINUED) [ADJRESNS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/ADJRESNS, April 22, 2021.