<P> During 2016, the initial balance as of January 1 was $2,780 billion . An additional $710 billion in payroll tax revenue and $87 billion in interest added to the Fund during 2016, while expenses of $776 billion were removed from the Fund, for a December 31, 2016 balance of $2,801 billion (i.e., $2,780 + $710 + $87 - $776 = $2,801). </P> <P> On February 2, 2005, President George W. Bush made Social Security a prominent theme of his State of the Union Address . One consequence was increased public attention to the nature of the Social Security Trust Fund . Unlike a typical private pension plan, the Social Security Trust Fund does not hold any marketable assets to secure workers' paid - in contributions . Instead, it holds non-negotiable United States Treasury bonds and U.S. securities backed "by the full faith and credit of the U.S. government". The trust funds have been invested primarily in non-marketable Treasury debt, first, because the Social Security Act prohibits "prefunding" by investment in equities or corporate bonds and, second, because of a general desire to avoid large swings in the Treasuries market that would otherwise result if Social Security invested large sums of payroll tax receipts in marketable government bonds or redeemed these marketable government bonds to pay benefits . </P> <P> The Office of Management and Budget has described the distinction as follows: </P> <P> These (Trust Fund) balances are available to finance future benefit payments and other Trust Fund expenditures--but only in a bookkeeping sense...They do not consist of real economic assets that can be drawn down in the future to fund benefits . Instead, they are claims on the Treasury that, when redeemed, will have to be financed by raising taxes, borrowing from the public, or reducing benefits or other expenditures . The existence of large Trust Fund balances, therefore, does not, by itself, have any impact on the Government's ability to pay benefits . </P>

When was the social security trust fund first raided