Sometimes, life circumstances prevent you from completing an adoption while your stepchild is still a minor. Now that they are an adult, you might be wondering if it is still possible and what the requirements are. This post covers those questions and also highlights the benefits of this process.
What you need to know about legal requirements
Under Arizona laws, an adult is permitted to adopt a current or former stepchild, regardless of the stepchild’s age. Unlike adoptions of nonrelatives, which restrict the adoptee’s age to 18 to 21, adoptions of stepchildren and other relatives, such as nieces, nephews, cousins or grandchildren, have no age limit.
A major requirement is that both you and your stepchild must agree to the adoption, and if either you or your stepchild is married, the consent of the spouse is also required. Another involves where you file the paperwork. Under state law, you may file the petition in the county where either you or your stepchild currently resides.
How to file for adult stepchild adoption
Your petition must include the following information:
- The length and nature of your relationship with your stepchild
- Your reason for seeking the adoption
- Why the adoption serves the best interests of both parties and the public
- Names and addresses of any living parents or adult children of your stepchild
- Details of any previous adult adoptions you or your spouse completed
Before the hearing date, a court-appointed individual will submit a written report evaluating the welfare and best interests of all parties involved. Both you and your stepchild must attend the court hearing in person. If you are unable to appear, an attorney may attend on your behalf, provided they have your written authorization.
What changes after the adoption
This process creates a legal parent-child relationship with all the rights and responsibilities that come with it. Your adult stepchild gains full inheritance rights from you, just as a biological child would under Arizona law. This change can simplify estate planning and ensure your stepchild receives the benefits you intend.
Conversely, the adopt adoption terminates the biological parent’s right to inherit from your stepchild and your stepchild’s right to inherit from the biological parent. This does not apply to the biological parent to whom the stepparent is married.
Finally, the adoption grants you and your stepchild formal recognition of your existing bond. Many families find this acknowledgment meaningful, especially when the relationship has existed for many years.

