Under the public charge rule, immigrants to United States classified as Likely or Liable to become a Public Charge may be denied visas or permission to enter the country due to their disabilities or lack of economic resources. The term was introduced in the Immigration Act of 1882. The restriction has remained a major cause for denial of visas and lawful permanent residency ever since; in 1992, about half of those denied immigrant and non-immigrant visas for substantive reasons were denied due to the public charge rule. However, the administrative definition of "public charge" has been subject to major changes, notably in 1999 and 2019.