A more thorough explanation:

Public charge refers to an immigrant who receives public benefits that could make them ineligible to become a permanent resident. According to the law, any immigrant who is likely to become a public charge at any time is not allowed to enter or stay in the United States.

The United States Citizenship and Immigration Services (USCIS) has the power to define public charge through regulations. In 2019, a regulation was passed that stated any immigrant who received one or more designated public benefits for more than 12 months within a 36-month period would generally be ineligible to become a permanent resident. However, in 2021, USCIS stopped enforcing this rule and instead applied the 1999 Interim Field Guidance.

The 1999 Interim Field Guidance defines public charge as an immigrant who has become primarily dependent on the government for subsistence, as demonstrated by either the receipt of public cash assistance for income maintenance or institutionalization for long-term care at government expense. This means that USCIS will not consider an applicant's receipt of Medicaid (except for long-term institutionalization at the government's expense), public housing, or Supplemental Nutrition Assistance Program (SNAP) benefits as part of the public charge inadmissibility determination.

• An immigrant who receives food stamps (SNAP) for more than 12 months within a 36-month period may be considered a public charge and ineligible to become a permanent resident under the 2019 regulation. However, under the 1999 Interim Field Guidance, this benefit would not be considered in the public charge determination.
• An immigrant who is institutionalized for long-term care at government expense may be considered a public charge under both the 2019 regulation and the 1999 Interim Field Guidance.

These examples illustrate how the definition of public charge can vary depending on the regulations in place. It is important for immigrants to understand the current rules and regulations regarding public charge to ensure they are eligible to become permanent residents.