The G Category

The G category of visas is reserved for diplomats and other officials of foreign countries who travel and work in the United States. The visa doesn't make the holder eligible for permanent residency or allow them to work in any non-designated business or organization.

Other G Visas

G-1 visas are for permanent mission members of a recognized government. G-2 visas are for representatives of recognized governments traveling temporarily to attend meetings. G-3 visas cover travel for representatives of non-recognized or non-member governments.

Immediate Family

The G-4 visa also covers the employee's immediate family, but they must also fill out an application. Eligible family members are the visa holder's spouse and unmarried children.

G4 Visa Requirements

An applicant for a G-4 visa is not required to be fingerprinted and an interview is usually not required, although any U.S. consular office can request one.

Limitations

Although a G-4 visa allows a person to travel to the United States, it does not guarantee the person entry into the country. Permission must be given by a U.S. immigration inspector at the point of entry.

Source:

G Visa FAQ: U.S. Dept of State

G Visa Overview: U.S. Dept. of State