29 USC 1102 - Establishment of plan

(a) Named fiduciaries 

(1) Every employee benefit plan shall be established and maintained pursuant to a written instrument. Such instrument shall provide for one or more named fiduciaries who jointly or severally shall have authority to control and manage the operation and administration of the plan.
(2) For purposes of this subchapter, the term named fiduciary means a fiduciary who is named in the plan instrument, or who, pursuant to a procedure specified in the plan, is identified as a fiduciary
(A)  by a person who is an employer or employee organization with respect to the plan or
(B)  by such an employer and such an employee organization acting jointly.
(b) Requisite features of plan 
Every employee benefit plan shall
(1) provide a procedure for establishing and carrying out a funding policy and method consistent with the objectives of the plan and the requirements of this subchapter,
(2) describe any procedure under the plan for the allocation of responsibilities for the operation and administration of the plan (including any procedure described in section 1105 (c)(1) of this title),
(3) provide a procedure for amending such plan, and for identifying the persons who have authority to amend the plan, and
(4) specify the basis on which payments are made to and from the plan.
(c) Optional features of plan 
Any employee benefit plan may provide
(1) that any person or group of persons may serve in more than one fiduciary capacity with respect to the plan (including service both as trustee and administrator);
(2) that a named fiduciary, or a fiduciary designated by a named fiduciary pursuant to a plan procedure described in section 1105 (c)(1) of this title, may employ one or more persons to render advice with regard to any responsibility such fiduciary has under the plan; or
(3) that a person who is a named fiduciary with respect to control or management of the assets of the plan may appoint an investment manager or managers to manage (including the power to acquire and dispose of) any assets of a plan.