Firearm transfers are exempt from the requirement for a NICS background check in three situations:

1. Transfers to transferees who have a state permit that has been recognized by ATF as an alternative to a NICS check;
2. Transfers of National Firearms Act weapons to persons approved by ATF; and
3. Transfers certified by ATF as exempt because compliance with the NICS background check requirement is impracticable.

[18 U.S.C. 922(t); 27 CFR 478.102(d)]