Adult Stepchild Adoption: Consent, Forms and Court Steps

The short answer: yes, you can adopt your stepchild after they turn 18, and it's usually one of the simplest cases a family court sees. In an adult adoption, the key consent is your adult stepchild's own. The other biological parent generally doesn't get a veto: California's courts say birth parents don't need to consent, and Texas law requires only the adult's written consent. Some states, such as Florida, still require that the parents get notice of the final hearing, which is a routine step, not an obstacle.

Why Families Adopt an Adult Stepchild

Many stepparents raised their stepchild for years but never adopted while the child was a minor. Sometimes the other parent was in the picture; sometimes life simply got in the way. Once the child is an adult, the adoption becomes a choice two grown people make together, and courts treat it that way.

Families tell us they adopt an adult stepchild to make an existing parent-child relationship official, to give the child the family's last name, to simplify inheritance, or simply because it matters to them. Whatever your reason, the court is formally recognizing a relationship that already exists.

Step 1: Talk About the Decision Together

Before you fill out anything, sit down with your adult stepchild and talk through what the adoption will do:

• A new legal parent-child relationship. In Texas, for example, an adopted adult becomes the adoptive parent's child for all purposes and inherits from the adoptive parent as a biological child would (Tex. Fam. Code § 162.507).
• Effects on the other biological family. Texas law also says the adopted adult can no longer inherit from the biological parent, and that parent can't inherit from the adult (same section). Other states have their own inheritance rules, so read your state's guide if this matters to your family.
• A name change, if wanted. Many adult adoptees ask for the family name in the same case. Decide on the exact new name before you file.

Write down a short, honest description of your relationship: how long you've been part of each other's lives and why you want legal recognition now. The judge may ask about it at the hearing.

Step 2: Check Your State's Age and Eligibility Rules

Adult adoption is available in many states, including California, Texas and Florida, but the details differ. Two examples from official sources:

• California. The adopting person must be older than the adult being adopted. A person generally can't adopt more than one unrelated adult, with exceptions such as a biological sibling of someone already adopted. A stepchild is related to you by marriage, so check how your situation fits. You file in the county where you live or where the adult lives (California Courts self-help guide).
• Texas. An adult living in Texas may petition to adopt another adult, and the case is filed in the petitioner's county of residence (Tex. Fam. Code §§ 162.501–162.502). Texas law doesn't set an age-gap requirement for adult adoptions.

Your state guide covers the rules where you live. Use your state's adult adoption process, not a packet built for adopting a minor; the documents are different.

Step 3: Sort Out Who Signs

Your adult stepchild

This is the consent that matters most. Texas requires the adult's written consent to be adopted (Tex. Fam. Code § 162.504). Florida requires written consent from the adult and from the adult's spouse, if any; the court can waive the spouse's consent for good cause (Fla. Stat. § 63.062(8)).

Your spouse

Your spouse is usually the adoptee's biological parent, and your spouse's role in the paperwork is set by your state. In Texas, both spouses must join a married petitioner's adult adoption petition, and the court can grant the adoption to just one spouse when the spouses ask (Tex. Fam. Code §§ 162.503, 162.506). In California, the adopting person's spouse or domestic partner must consent, and so must the adoptee's spouse or partner, if any.

The other biological parent

Here's the part that worries families most, and it's usually the easiest. In an adult adoption, the other biological parent generally doesn't have to agree. California's courts say plainly that birth parents don't need to consent, although the court may let them know about the hearing. Texas requires only the adult's consent.

Some states do require notice. Florida, for example, requires written notice of the final hearing to the adult's parents, or proof that notice was served (Fla. Stat. § 63.062(8)). Notice simply tells the parent the hearing is happening; it doesn't give them the power to stop an adoption that your adult stepchild wants. If you don't know where the parent lives, your state's rules provide a way to give notice anyway. See the Florida filing checklist for an example.

Step 4: Prepare Your Documents

An adult adoption packet is usually shorter than a minor adoption packet. In California, for example, the court's list includes an adoption agreement, a petition, any spouse or partner consents, and an order of adoption, plus a Court Report of Adoption (VS-44) if the adult is changing their name. Other states use their own forms, but the pieces are similar:

Step 5: File and Attend the Hearing

File your packet with the clerk of the right court in your county and pay the filing fee, which varies by county. The clerk will tell you how many copies to bring and how the hearing is scheduled.

The hearing is usually short and warm. In California, the judge confirms that both of you understand and agree to the adoption and that it's in the best interest of both of you. Texas requires both the petitioner and the adult to attend, though the court can waive attendance for good cause (Tex. Fam. Code § 162.505). Bring certified copies of your key documents and anyone who's supposed to be there.

Step 6: Update Records After the Adoption

Once the judge signs the order, the adoption is final. Order several certified copies, then:

1. Request an amended birth certificate from the vital records office in the state where your stepchild was born.
2. Update Social Security if the name changed, then the driver's license, passport, bank and other accounts.
3. Review estate plans: wills, trusts and beneficiary designations, for both of you.

The adoption order doesn't update every record by itself. Each agency has its own process, so bring a certified copy to each one.

For more detail, see the adult adoption forms guide, the adult adoption cost guide and our adult adoption overview.

Frequently Asked Questions

Can I adopt my stepchild after they turn 18?

Yes. Many states, including California, Texas and Florida, let one adult adopt another, and adopting an adult stepchild is a common reason families use it. Your state sets the eligibility rules, such as California's rule that the adopting person must be older than the adoptee.

Does the biological father have to consent to an adult adoption?

Generally, no. The key consent is your adult stepchild's. California's courts say birth parents don't need to consent, and Texas law requires only the adult's written consent. Some states, like Florida, require that the parents receive notice of the final hearing, but notice isn't the same as a veto.

Does my spouse have to be part of the case?

Usually, yes, in some form. Texas requires both spouses to join a married petitioner's petition, and California requires the adopting person's spouse or domestic partner to consent. Your state guide explains the rule where you live.

Can my adult stepchild take our last name?

Yes, a name change is commonly requested in the same adoption case. Put the exact new name in the petition and proposed order, then update Social Security and other records after the order is signed.

How much does an adult stepchild adoption cost?

StepParent Adoption 360 prepares the document package for $349 for the first adult and $99 for each additional adult. Court filing fees, any service of notice and certified copies are paid separately and vary by county.

About the Author

Doug Brown, Founder. Doug Brown has helped families prepare stepparent and adult adoption paperwork since 2001: more than 34,000 families in all 50 states. StepParent Adoption 360 is a document-preparation service, not a law firm, and doesn't give legal advice.

Sources: California Courts self-help guide, "Adult adoption" (selfhelp.courts.ca.gov); Tex. Fam. Code §§ 162.501–162.507; Fla. Stat. § 63.062(8) (2026). Company figure (34,000+ families since 2001) is from our own records.