The FRED series Total Credit Market Assets Held by Domestic Financial Sectors - Agency- and GSE-Backed Mortgage Pools is now known as Agency-and GSE-Backed Mortgage Pools; Total Mortgages; Asset.
The source series id is FL413065005.Q.
This series appears in Table L.214. For further information see the assistance provided in the guide to the Financial Accounts at http://www.federalreserve.gov/apps/fof/.
Board of Governors of the Federal Reserve System (US), Agency-and GSE-Backed Mortgage Pools; Total Mortgages; Asset, Level [AGSEBMPTCMAHDFS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/AGSEBMPTCMAHDFS, January 21, 2018.