Maryland Health - General Section 18-4A-03
§ 18-4A-03.
  (a)   Subject to the provisions of this section, the following individuals, not in order of priority, may consent to the immunization of a minor if a parent is not reasonably available and the authority to consent is not denied under subsection (b) or (c) of this section:
    (1)   A grandparent;
    (2)   An adult brother or sister;
    (3)   An adult aunt or uncle;
    (4)   A stepparent;
    (5)   Any other adult who has care and control of the minor;
    (6)   A court that has jurisdiction of a suit affecting the parent-child relationship of which the minor is the subject;
    (7)   An adult who has care and control of the minor under an order of a court or by commitment by a court to the care of an agency of the State or county if the adult reasonably believes the minor needs immunization; or
    (8)   For minors in its care and custody, the Department of Juvenile Services.
  (b)   A person may not consent to the immunization of a minor under subsection (a) of this section if:
    (1)   The person has actual knowledge that the parent has expressly refused to give consent to the immunization; or
    (2)   The parent has told the person that the person may not consent to the immunization of the minor or, in the case of a written authorization, has withdrawn the authorization in writing.
  (c)   When a parent has been contacted and requested to consent to the immunization of a minor, the Department of Juvenile Services may consent to the immunization of a minor in its care and custody if the parent:
    (1)   Has not acted on the request; and
    (2)   Has not expressly denied to the Department of Juvenile Services the authority to consent to the immunization of the minor.
  (d)   For purposes of this section, a person is not reasonably available if:
    (1)   The location of the person is unknown;
    (2)   (i)   A reasonable effort made by a person listed in subsection (a) of this section to locate and communicate with the parent for the purpose of obtaining consent has failed; and
      (ii)   Not more than 90 days have passed since the date that the effort was made; or
    (3)   The parent has been contacted by a person listed in subsection (a) of this section and requested to consent to the immunization of the minor, and the parent:
      (i)   Has not acted on the request; and
      (ii)   Has not expressly denied authority to the person listed in subsection (a) of this section to consent to immunization of the minor.
  (e)   A person authorized to consent to the immunization of a minor under this section shall confirm that the parent is not reasonably available in writing and the written confirmation shall be included in the minor's medical record.