26 CFR §1.401-0

1. (a)In general. Sections 1.401 through 1.401-14 (inclusive) reflect the provisions of section 401 prior to amendment by the Employee Retirement Income Security Act of 1974. The sections following § 1.401-14 and preceding § 1.402(a)-1 (hereafter referred to in this section as the “Post-ERISA Regulations”) reflect the provisions of section 401 after amendment by such Act.
2. (b)Definitions. For purposes of the Post-ERISA regulations—
   1. (1)Qualified plan. The term “qualified plan” means a plan which satisfies the requirements of section 401(a).
   2. (2)Qualified trust. The term “qualified trust” means a trust which satisfies the requirements of section 401(a).