Federal law explicitly prohibits foreigners from immigrating to the U.S. if they are "likely at any time to become a public charge," meaning a burden on taxpayers. This law does not exclude immigrants who are poor but those who cannot or will not work and those who are likely to rely on taxpayers to provide for their personal needs. In spite of this law, from 1999 to February 2020, the federal government operated under guidelines issued by President Clinton to ignore welfare benefits like Medicaid, Food Stamps, housing, Head Start, and utility assistance. In August 2019, President Trump issued a regulation to consider such benefits in immigration applications. After a series of court challenges, Trump's regulation became effective nationwide in February 2020.