The A-3 visa is a non-immigrant visa which allows travel to United States for attendants, servants, and employees of those in the US under A-1 or A-2 visas. A-3 recipients fall into two categories: those paid by the principal applicant's home government, and domestic employees paid by the principal applicant themselves. The maximum duration of stay is three years, and individuals are exempt from US taxes.
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A-3 visa Wikipedia(Text) CC BY-SA