U.S. Citizenship and Immigration Services allows the spouse and unmarried children under 21 of an 'H' (H-1A / H-1B / H-2A / H-2B / H-3) visa holder to obtain H-4 visas to live in the U.S. These visas are usually issued at the U.S. consulate office in the intending nonimmigrant’s home country. However, if the individual is already in U.S., they may obtain an H-4 visa by filing for a change of status.
H-4 visa holders are not allowed employment in the U.S. and are not eligible to get a Social Security Number. However, an H-4 visa holder can obtain a drivers license, open bank account(s) and get an ITIN for tax purposes. An H-4 visa holder is admitted to the U.S. for the duration of the primary ‘H’ status.