Maryland Code, Family Law § 5-306

(1) the man was married to the child's mother at the time of the child's conception;

(2) the man was married to the child's mother at the time of the child's birth;

(3) the man is named as the father on the child's birth certificate and has not signed a denial of paternity;

(4) the child's mother has named the man as the child's father and the man has not signed a denial of paternity;

(5) the man has been adjudicated to be the child's father;

(6) the man has acknowledged himself, orally or in writing, to be the child's father and the mother agrees; or

(7) on the basis of genetic testing, the man is indicated to be the child's biological father.

(b)(1) A petitioner under Part II or Part III of this subtitle shall give a juvenile court notice that a man who is not named in the petition and has not been excluded as a father claims paternity.

(2) After a request of a party or claimant and before ruling on a petition under Part II or Part III of this subtitle, a juvenile court shall hold a hearing on the issue of paternity.