Utah Code § 75A-9-122: Immunity.

(1) A health care professional or health care institution acting in good faith is not subject to civil or criminal liability or to discipline for unprofessional conduct for:

(a) complying with a health care decision made for an individual by another person if compliance is based on a reasonable belief that the person has authority to make the decision, including a decision to withhold or withdraw health care;

(b) refusing to comply with a health care decision made for an individual by another person if the refusal is based on a reasonable belief that the person lacked authority or capacity to make the decision;

(c) complying with an advance health care directive based on a reasonable belief that the directive is valid;

(d) refusing to comply with an advance health care directive based on a reasonable belief that the directive is not valid, including a reasonable belief that the directive was not made by the individual or, after its creation, was substantively altered by a person other than the individual who created it; or

(e) determining that an individual who otherwise might be authorized to act as an agent or default surrogate is not reasonably available.

(2) An agent, default surrogate, or individual with a reasonable belief that the individual is an agent or a default surrogate is not subject to civil or criminal liability or to discipline for unprofessional conduct for a health care decision made in a good faith effort to comply with Section 75A-9-116.