"Immigration law in the United States has long contained exclusion and removal provisions designed to limit government spending on indigent non-U.S. nationals (aliens). Under the Immigration and Nationality Act (INA) ,an alien may be denied admission into the United States or adjustment to lawful permanent resident (LPR) status if he or she is 'likely at any time to become a public charge.'An admitted alien may also be subject to removal from the United States based on a separate public charge ground of deportability, but this ground is rarely employed. Certain categories of aliens, such as refugees and asylees, are exempted from application of the public charge grounds.The Department of Homeland Security (DHS) and the Department of State (DOS) have primary responsibility for implementing the INA's public charge provisions. DHS's U.S. Citizenship and Immigration and Services may make a public charge determination when an alien applies to adjust to LPR status. Abroad, DOS consular officers may make a public charge determination when an alien applies for a visa."
CRS Report for Congress, R45313
Congressional Research Service: https://crsreports.congress.gov/