The FRED series Total Credit Market Assets Held by Domestic Financial Sectors - Private Pension Funds is now known as Private Pension Funds; Debt Securities and Loans; Asset, Level.
The source series id is FL574004005.Q.
The series previously appeared in Table L.1, but is updated in the underlying data set. 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), Private Pension Funds; Debt Securities and Loans; Asset, Level [PPFTCMAHDFS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/PPFTCMAHDFS, June 23, 2018.