Can You Take Custody of a Sibling at 18? All You Need to Know

Can You Take Custody of a Sibling at 18? All You Need to Know

Parents automatically have the right to decide most things for their younger children since they have natural custody rights. However, can you take custody of a sibling at 18 if your parents cannot care for them? According to Lawyersnlaws, the answer is yes, but only in states where you reach the age of majority at 18.

Additionally, you must prove to the court that your parents are unfit to raise your sibling and that your guardianship would be in your sibling’s best interest.

Sibling Custody: Can You Take Responsibility at 18?

Under the law, parents are the automatic guardians of their children. Among the crucial decisions parents make for their children are their health, where they reside, their education, and religion.

Even though the biological parents have the right to decide on the child, a court can terminate these rights if they cannot provide proper care. When both parents are dead or unfit to provide for their child, courts prefer to grant custody to an adult sibling or close relative rather than seek external options.

When a parent’s lifestyle does not offer a safe and nurturing environment for their child, for example, they abandon the child, fail to provide for it, or the child suffers any form of physical or mental abuse, a court can find them incapable and take away their right.

In cases where both parents die without a will affirming who will be responsible for the child, courts will listen to a petition from third parties for custody. However, courts prefer close relatives of the child, including grandparents, aunts and uncles, and siblings. They will sometimes also consider close family friends.

Taking on Sibling Custody: What You Need to Know at 18

When you decide to take your parents to court for custody of a sibling, you must prove that your guardianship is necessary for the child. Court proceedings are often tricky, and it’s a good idea first to determine if proceeding with the custody appeal is needed.

Start by speaking to the child’s legal parents, explaining why you think they should relinquish legal custody to you. Some parents know they cannot take good care of their child and will agree that you can provide better care.

If they agree, then the procedure for filing a petition to take over as the guardian is much easier. Besides the petition, you must also file several forms to the court in the county where the child resides. It’s best to get assistance from an attorney. Depending on the state, you can take the papers to court for filing with the court’s clerk or do the process online.

Additionally, it’s good to know if there is a separate custody case for your sibling in another court or if there’s another custody order elsewhere. If there is, you may need to petition the court that already has the existing order to prevent inconsistencies. As you can see, these are important issues, and an attorney is the best person to advise you.


As in all custody cases, the court always looks at the child’s best interests. You must prove that your sibling’s parents are unfit and not capable. LegalMatch provides the following list of things that you must offer your sibling once you get custody:

  • Food
  • Housing Education
  • Clothing
  • Medical Care
  • Stability at home

Don’t assume the court will take your word that you can offer all the above. It may order an investigator to visit your home to see how you live and to interview you. They may do the same with your sibling. These steps ensure you can provide for the child in every way, including financially and emotionally, and that your guardianship is in the child’s best interest before deciding on awarding custody.

Courts will also consider the preferences of older children in custody cases like these. In a family with many minor children, an older sibling might have to show the court that when they have custody of one sibling, they will do everything possible to preserve the family unit if they cannot take all the children.

Custody of Siblings at 18: Exploring Your Options

These are the four options for taking custody of a sibling at 18:

  1. Parents are deceased or unavailable: In cases where both parents are dead, incarcerated, or can’t be located, you can apply to take custody of a sibling if you are 18. In this situation, you must follow the legal actions required to apply to the courts for custody. Things can get tricky if other relatives also want custody of the child.
  2. Parents are incapable of being guardians: If the parents have a physical or mental disability that doesn’t allow them to care for your sibling correctly, you can apply to the court for custody at 18. You must show the court that you can care for your sibling adequately.

In both cases, you must prove you have financial stability and emotional maturity to take custody of a sibling.

The court will ask you to prove that you can care for a sibling’s monetary needs by providing proof of having a job or other regular income source. A savings account is another plus since it shows you can provide for yourself and your sibling. If you don’t have very high earnings but have family or friends willing to contribute financially, the court will consider the circumstances.

You can prove emotional maturity by providing the court with documentation like references from a mentor, employer, teacher, etc. You can also provide financial statements showing your capability to handle your finances.

Courts will let you take custody of a sibling at 18 once you have proved you have the financial means and maturity. Otherwise, they will prefer to give custody to an older family member.

Legal Considerations: Taking Custody of a Sibling at 18

Courts prefer children to live with their biological parents. The only time they will consider legally giving custody to a sibling of 18 is in the following circumstances:

  • Both of your sibling’s parents are deceased
  • Both parents are physically or mentally incapacitated
  • Your sibling suffers from abuse or neglect by their parents
  • One or both the parents are incarcerated or have addictions
  • Any other reasons that make it impossible for the biological parents to care for the child

Sibling Custody at 18: Navigating the Challenges

You cannot decide to take over custody of a sibling without initiating a court filing and getting a court order. However, as mentioned above, a court will examine various factors before deciding on the child’s best interests.

They especially look at the following:

  • The wishes of a child if they are old enough capable of choosing
  • Parental mental and physical health
  • The necessity of maintaining a stable home environment
  • The child’s interaction and relationships with the other members of the family and the household in general
  • The adjustment of the child to a new school and community
  • The court looks for evidence of domestic violence, physical or emotional abuse, or parental drug and alcohol abuse.

The court will also consider the relevance of other children and sibling custody before determining if granting you guardianship is in the child’s best interest.

To gain legal custody of a sibling, you must be over 18 in most states or have legal emancipation. States have different procedures for filing a custody request with the court. In most states, you fill in certain forms and provide the relevant documentation. Your sibling you want custody of must be under 18 or legally dependent on their parents.

Is Sibling Custody Possible at 18? Key Factors to Consider

It is important to remember that custody laws differ between states. Therefore, the process can become complicated if you don’t live in the same state as your sibling. The same applies if your sibling’s parents contest your petition for custody. More complications can arise in cases where the child you want to take in your custody is disabled or has significant assets in its name.

In cases where the parents are still alive and agree to allow an older sibling to take custody, the court will only agree if they feel the placement is necessary after closely examining the circumstances. If one parent is against you taking guardianship, the child’s interests and safety come first when the court decides.

Final Take

Can you take custody of a sibling at 18? The conclusion is yes. But you must prove that the parents are incapable and you can meet the court’s requirements. Since other family members can also apply for custody or guardianship, remember that the court has a right to consider all options before deciding where the child’s best interests lie. Custody cases are complex, and each state has its own laws. You can file for custody pro se, meaning you represent yourself in court. But  it’s best to have a family law attorney on your side to provide the best advice and assistance when filing forms and during proceedings.