The FRED series Treasury Securities - Assets - Balance Sheet of Nonfarm Noncorporate Business is now known as Nonfinancial Noncorporate Business; Total U.S. Government Securities; Asset.
The source series id is FL113061003.Q.
This series appears in Table B.104. 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), Nonfinancial Noncorporate Business; Total U.S. Government Securities; Asset, Level [TSABSNNB], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/TSABSNNB, April 25, 2018.