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29 U.S. Code § 1110 - Exculpatory provisions; insurance

(a)
Except as provided in sections 1105(b)(1) and 1105(d) of this title, any provision in an agreement or instrument which purports to relieve a fiduciary from responsibility or liability for any responsibility, obligation, or duty under this part shall be void as against public policy.
(b) Nothing in this subpart [1] shall preclude—
(1)
a plan from purchasing insurance for its fiduciaries or for itself to cover liability or losses occurring by reason of the act or omission of a fiduciary, if such insurance permits recourse by the insurer against the fiduciary in the case of a breach of a fiduciary obligation by such fiduciary;
(2)
a fiduciary from purchasing insurance to cover liability under this part from and for his own account; or
(3)
an employer or an employee organization from purchasing insurance to cover potential liability of one or more persons who serve in a fiduciary capacity with regard to an employee benefit plan.