Adoption is a common practice throughout the world and throughout history. However, laws regulating adoption vary from country to country. People seeking to adopt in a country other than the one in which they live, a process known as international adoption, should familiarize themselves with the laws of that country. Similarly, although every U.S. state recognizes adoption, state laws regarding specific aspects of adoption vary. Some states recognize adoptions by two people of the same sex or adoptions by a man and woman who are not married to one another.
Many states also allow the adoption of adults.
Some states preserve the rights of an adopted adult to inherit from his or her biological parents after the adoption. Adoptions may be open or closed. An open adoption involves some exchange of personal information. At the very least, one party will furnish information relevant to the child's future well-being, such as medical history or financial status. In some cases, the biological parents may maintain personal contact with the child after the adoption.