There are many reasons for adult adoption. My daughter chose to be adopted as an adult by my husband, her stepfather, to formally acknowledge the relationship that they had as a parent and a child. Because she also had a relationship with her biological father, he would not allow the adoption to take place when she was a minor. She felt strongly that her relationship with her biological father was not parental in nature, and wanted to make her stepfather her legal father. By making the relationship legal, it also means that she can inherit from him.
Considering Adoption? We can help. Adult adoptions are more common than ever, and they can occur in a wide range of situations. Stepparents often adopt their grown stepchildren, and foster parents often adopt their long-time foster children when they reach 18 years of age.