26 CFR §31.3121(b)(9)-1 — (b)(9)-1 Railroad industry; services performed by an employee or an employee representative as defined in section 3231.

Services performed by an individual as an “employee” or as an “employee representative”, as those terms are defined in section 3231, are excepted from employment. For definitions of employee and employee representatives, see §§ 31.3231(b)-1 and 31.3231(c)-1.