Maryland Family Law Section 5-203
(a)   (1)   The parents are the joint natural guardians of their minor child.
(2)   A parent is the sole natural guardian of the minor child if the other parent:
(ii)   abandons the family; or
(iii)   is incapable of acting as a parent.
(b)   The parents of a minor child, as defined in Article 1, § 24 of the Code:
(1)   are jointly and severally responsible for the child's support, care, nurture, welfare, and education; and
(2)   have the same powers and duties in relation to the child.
(c)   If one or both parents of a minor child is an unemancipated minor, the parents of that minor parent are jointly and severally responsible for any child support for a grandchild that is a recipient of temporary cash assistance to the extent that the minor parent has insufficient financial resources to fulfill the child support responsibility of the minor parent.
(d)   (1)   If the parents live apart, a court may award custody of a minor child to either parent or joint custody to both parents.
(2)   Neither parent is presumed to have any right to custody that is superior to the right of the other parent.