Essential support personnel may accompany P-1B entertainment groups and P-3 culturally unique aliens or groups. U.S. Citizenship and Immigration Services (USCIS) informally denotes their classification as P-1BS and P-3S respectively. Essential support personnel are supposed to be skilled persons whose services are integral and essential to the performance, though USCIS ordinarily does not demand much proof on this point. Nonetheless, it is advisable to eliminate unskilled personnel such as chauffeurs or personal servants coming simply for convenience. In practice, USCIS does not insist that support personnel have prior experience with the particular alien or group.

P support personnel may be grouped together in a single petition, but they must be petitioned for separately from the performers themselves. P support petitions may be filed with the main petition, which is preferable, or thereafter, but not before.