The Disability Insurance Trust Fund is a separate account in the United States Treasury. A fixed proportion (dependent on the allocation of tax rates by trust fund) of the payroll taxes received under the Federal Insurance Contributions Act and the Self-Employment Contributions Act are deposited in the fund to the extent that such taxes are not needed immediately to pay expenses. Taxes are deposited in the fund on every business day.

The trust fund provides automatic spending authority to pay monthly benefits to disabled-worker beneficiaries and their spouses and children. With such spending authority, the Social Security Administration does not need to periodically request money from the Congress to pay benefits.

Funds not withdrawn for current cost (benefits, the financial interchange with the Railroad Retirement program, and administrative expenses) are invested in interest-bearing Federal securities, as required by law; the interest earned is also deposited in the trust fund.

The Disability Insurance (DI) Trust Fund was created with passage of the Social Security Act Amendments of 1956. DI became effective on January 1, 1957.

The Board of Trustees currently consists of 6 members, 4 of whom automatically serve by virtue of their positions in the Federal Government. These 4 are the

  • Secretary of the Treasury (the Managing Trustee),
  • Secretary of Labor,
  • Secretary of Health and Human Services, and
  • Commissioner of Social Security
The other 2 members are appointed by the President, and confirmed by the Senate, as required by the "Social Security Amendments of 1983." These 2 members serve 4-year terms.