The FRED series Savings Bonds - Assets - Balance Sheet of Households and Nonprofit Organizations is now known as Federal Government; U.S. Savings Bonds; Liability.
The source series id is FL313161400.Q.
This series appears in Table B.101. 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), Federal Government; U.S. Savings Securities; Liability [SBABSHNO], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/SBABSHNO/, August 31, 2015.