42 USC 1654 - Persons excluded from benefits

This chapter shall not apply in respect to the injury or death of
(1)  an employee subject to the provisions of subchapter I of chapter 81 of title 5;
(2)  an employee engaged in agriculture, domestic service, or any employment that is casual and not in the usual course of the trade, business, or profession of the employer; and
(3)  a master or member of a crew of any vessel.