In the U.S. since 1978,[6] as of 2021[update], CFR Title 14 Part 250 requires airlines to first appeal for passengers to voluntarily release their seat.[7] The amount of compensation is not regulated.[7] If volunteers are insufficient, airlines will then refuse some passengers the right to board. In such case, since 1968,[8] Part 250 defines minimum compensation that must be paid.[7] However, passengers who failed to reconfirm do not receive this compensation.[7]