National Debt Holder Amount Description  
Social Security Trust Funds $2.67 trillion The largest portion of U.S. Intergovernmental Securities and the biggest holder of U.S. debt is the Federal Old-Age and Survivors Insurance Trust Fundand the Federal Disability Insurance Trust Fund,together comprising the Social Security Trust Fund or OASDI. When tax revenues for the Social Security exceed current expenses, the funds are legally obligated to invest in interest-bearing Federal securities guaranteed by the government, such as bonds from the U.S. Treasury.
U.S. Federal Reserve $1.659 trillion One of the biggest holders of U.S. government debt is actually within the United States itself. The Federal Reserve system of banks reports in its most recent balance sheet holdings of $1.659 trillion in U.S. Treasury debt as of May 24, 2012.
China $1.169 trillion The largest foreign holder of US Treasury securities, China posesses $1.169 trillion in American debt, although it is down from all time highs of $1.314 trillion in July 2011.
Savings Bonds & Other Investors $1.102 trillion With the most recent numbers from December 2011, this extremely diverse group includes individuals, government-sponsored enterprises, brokers and dealers, bank personal trusts, estates, savings bonds, corporate and non-corporate businesses for a total of $1.102 trillion.
Japan $1.083 trillion A major US trade partner, Japan holds a huge amount of American debt, and has traditionally been one of the US's largest debt holders, currently owning $1.083 trillion of treasury securities.
Pension Funds $903.4 billion Pension funds control large amounts of money, reserved for personal retirements, and thus are obligated to make investments that are considered to be safe. This group includes both private and local government pension funds, totaling $903.4 billion. The private pension fund category also includes US Treasury securities held by the Federal Employees Retirement System Thrift Savings Plan "G Fund."
Mutual Funds $797.9 billion According to the Federal Reserve, mutual funds hold the seventh largest amount of U.S. debt compared to any other group, and their holdings are currently at an all-time high. Including money market funds, mutual funds and closed-end funds, this group of investment funds manages approximately $797.9 billion of U.S. Treasury securities as of December 2011, which are the most recent numbers available.
State and Local Governments $444.6 billion U.S. state and local governments have nearly a half-trillion dollars invested in American debt, according to the Federal Reserve. The level of investment has remained very stable since 2006, moving within the range of $484 billion and $576 billion. The current debt holdings, however, represent the lowest aggregate level for state and local governments since June 2005, when they stood just below today’s figure at $444 billion.
Medicare Trust Funds $324.57 billion The trust funds supplying capital to Medicare - the Hospital Insurance Trust Fund and the Supplementary Medical Insurance Trust Fund - hold approximately $324.57 billion in U.S. Government debt, according to the Treasury. The Hospital Insurance Trust Fund draws revenue mostly from payroll taxes and pays for Medicare Part A benefits, including inpatient hospital care and home health care, along with program administration costs.
Depository Institutions $286.3 billion As of the fourth quarter of 2011 (the most recent numbers currently available), the Federal Reserve Board of Governors lists depository institutions as holding approximately $286.3 billion in U.S. debt. This group includes commercial banks, savings banks and credit unions and in 2011 holdings nearly tripled from the 2008 low of $105 billion.
Oil Exporters $254.5 billion Big oil means big money... and big investment into U.S. debt. Included in the group of oil exporters are Ecuador, Venezuela, Indonesia, Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, the United Arab Emirates, Algeria, Gabon, Libya, and Nigeria. The group combines for a total of $254.5 billion, just off the 2012 high of $264.9 billion.
Insurance Companies $253.7 billion According to the Federal Reserve Board of Governors, insurance companies hold $253.7 billion in Treasury securities. This group includes property-casualty and life insurance firms.
Brazil $237.4 billion The South American economic giant has $237.4 billion in holdings, according to the Treasury. Brazil’s investment into US debt has been fluctuating only slightly over the past two years, with current holdings remaining between $190 billion and $240 billion over the past 12 months.
Caribbean Banking Centers $224.8 billion The U.S. Treasury identifies this group as institutions in the Bahamas, Bermuda, the Cayman Islands, Netherlands Antilles, Panama and the British Virgin Islands. Holdings are currently listed at $224.8 billion, up from $106.6 billion in June 2008, but remains off the group's high of $226 billion in December 2011.
Taiwan $184.4 billion Taiwan's holdings of U.S. debt have increased gradually over the last year, but in the past two years it has surpassed both Russia and Switzerland in total holdings. To date, Taiwan holds $184.4 billion in Treasury securities, compared with Russia's $146.7 billion and Hong Kong’s $138.8 billion.