Indiana Code Title 16. Health § 16-36-7-40

Sec. 40. (a) A health care provider or other person who acts in good faith reliance on an advance directive or on a health care decision made by a health care representative with apparent authority is immune from liability to the declarant and to the declarant's heirs or other successors in interest to the same extent as if the health care provider or other person had dealt directly with the declarant and if the declarant had been competent and not incapacitated.

(b) A health care provider is not responsible for determining the validity of an advance directive.