Md. Code, Estates and Trusts § 4-505

(a) An individual may refuse to make an anatomical gift of the individual’s body or part by:

(1) A record signed by:

(i) The individual; or

(ii) Subject to subsection (b) of this section, if the individual is physically unable to sign, another individual acting at the direction of the individual;

(2) The individual’s will, whether or not the will is admitted to probate or invalidated after the individual’s death; or

(3) During a terminal illness of the individual or while the individual is injured, any form of communication addressed to at least two adults, at least one of whom is a disinterested witness.

(b) A record signed in accordance with subsection (a)(1)(ii) of this section shall:

(1) Be witnessed by at least two adults, at least one of whom is a disinterested witness, who have signed at the request of the individual; and

(2) State that the record has been signed and witnessed as provided in item (1) of this subsection.

(c) An individual who has made a refusal may amend or revoke the refusal:

(1) In a manner for making a refusal provided in subsection (a) of this section;

(2) By subsequently making an anatomical gift in accordance with § 4–503 of this subtitle that is inconsistent with the refusal; or

(3) By destroying or canceling the record evidencing the refusal, or the portion of the record used to make the refusal, with the intent to revoke the refusal.

(d) Except as otherwise provided in § 4–506(h) of this subtitle, in the absence of an express, contrary indication by the individual set forth in the refusal, an individual’s unrevoked refusal to make an anatomical gift of the individual’s body or part bars all other persons from making an anatomical gift of the individual’s body or part.