Can I Adopt My Adult Stepchild? Eligibility and Consent

The short answer: yes, you can adopt your adult stepchild, and it's usually simpler than adopting a minor. Many families do it years after the stepchild grew up, when they finally get around to making official a relationship that has been real all along. The key consent is your stepchild's own. Biological parents generally don't get a veto: California's court guide, for example, says birth parents don't need to consent, and Texas requires the adult's own written consent. Some states, such as Florida, require that the parents receive notice of the hearing, which is a routine step.

Start With Your Filing State

Adult adoption is handled under state law, and each state has a few basic rules. Start with the guide for your state. Two examples:

• California: the California Courts self-help guide covers adopting someone 18 or older and requires the adopting person to be older than the adult being adopted. You file in the county where you live or where your stepchild lives.
• Texas: Texas Family Code § 162.501 lets an adult residing in Texas petition to adopt another adult, in a district court or statutory county court with family-law jurisdiction in the county where the petitioner lives (§ 162.502). The adult adoption subchapter doesn't set an age-gap requirement.

Whose Consent Do You Need?

Your stepchild's. This is the one that matters most. Texas, for example, says the court may not grant the adoption unless the adult consents in writing (Tex. Fam. Code § 162.504).

Spouses. In Texas, if the person adopting is married, both spouses must join the petition (§ 162.503). If you're adopting your spouse's adult child, that's usually exactly what you both want anyway. In California, the adopting person's spouse or domestic partner, and the adult stepchild's spouse or domestic partner, must consent.

The other biological parent. Generally not. In California, Texas and Florida, for example, the rules for adult adoption don't give the biological parents a right to block it. California's court guide says birth parents don't need to consent, though the court may let them know about the hearing.

What If the Other Biological Parent Doesn't Agree?

In most states it doesn't change anything, because the other parent isn't asked to agree. A few states require notice: Florida Statutes § 63.062(8) requires written consent from the adult and the adult's spouse, if any (the court can waive the spouse's consent for good cause), and written notice of the final hearing to the adult's parents. Notice tells them the hearing is happening; it isn't a request for permission.

If someone actively objects, or there's a question about whether your stepchild can give consent, that's a good time to talk with a local attorney. Most adult stepchild adoptions are simple, agreed cases.

What If I Was Never Married to My Stepchild's Parent?

Adult adoption usually isn't limited to stepparents. California's process covers adult adoptions generally, and Texas's statute lets a Texas resident adopt another adult. So a long-time partner of the child's parent can often use the same adult adoption process. Check your state guide for any relationship or residence rules.

What Changes After the Adoption?

You become your stepchild's legal parent. Inheritance is the change families ask about most, and states handle it differently. In Texas, the adopted adult inherits from the adoptive parent like a biological child, and no longer inherits from or through the biological parent (Tex. Fam. Code § 162.507). If inheritance is a big part of your reason for adopting, read your state's rule or talk with an estate-planning attorney. If your stepchild is changing their name, the certified adoption order is what you use to update Social Security, the DMV and other records.

Prepare a Simple Checklist

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

Frequently Asked Questions

Can I adopt my stepchild after they turn 18?

Yes. Adult adoption is available for stepchildren who are 18 or older, and it's often simpler than a minor adoption because your stepchild gives their own consent.

Does the biological father have to agree to an adult stepchild adoption?

Generally, no. Your adult stepchild's consent is what's required. Some states, such as Florida, require that the parents receive notice of the final hearing.

Does my spouse need to be involved?

Usually, yes. In Texas, both spouses join the petition; in California, your spouse consents. Since you're adopting your spouse's child, this is normally a formality.

How much does it cost to adopt an adult stepchild?

StepParent Adoption 360's preparation is $349 for the first adoptee and $99 for each additional adoptee. Court filing fees and certified copies are separate and vary by county.

Will my stepchild get a new birth certificate?

The adoption order is the document you use to request one from the vital records office in the state where your stepchild was born, following that office's procedure.

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"; Texas Family Code §§ 162.501–162.507; Florida Statutes § 63.062(8) (2026). Company figures (34,000+ families since 2001) are from our own records.