Adopting an adult from another country is legal in nearly every U.S. state, and the state court process itself is usually straightforward. What it will not do is bring that person into the country or give them any U.S. immigration status. Federal immigration law only treats an adopted person as a “child” for visa sponsorship if the adoption happened before age 16, so an adult adoption cannot be used to obtain a green card or citizenship for the adoptee.1Office of the Law Revision Counsel. 8 U.S. Code 1101 – Definitions The state-level adoption is real and creates a legal parent-child relationship for purposes like inheritance and medical decisions. The immigration door stays closed.
Why the Adoption Will Not Bring Them to the U.S.
This is the point that trips up almost everyone who looks into international adult adoption, so it belongs first. Federal immigration law defines an adopted “child” as someone adopted while under age 16 who also lived in the legal custody of the adopting parent for at least two years.1Office of the Law Revision Counsel. 8 U.S. Code 1101 – Definitions Someone adopted for the first time at 18, 25, or 40 does not meet that definition, no matter how genuine the relationship.
In practical terms, you cannot file an I-130 immigrant visa petition to sponsor an adult adoptee as your child or immediate relative unless the adoption originally took place before the person turned 16 and met the legal requirements at that time. USCIS does allow petitions for adopted sons and daughters over 21, but only when the adoptee previously qualified as an adopted child under immigration law.2U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 5, Part E, Chapter 2 – Eligibility A first-time adult adoption never clears that initial hurdle.
If bringing the person to the United States is the actual goal, adult adoption is the wrong tool. Employment-based visas, the diversity lottery, or other family-based categories may be worth exploring with an immigration attorney, but they operate independently of any adoption you finalize in state court.
The Hague Convention Does Not Apply
The Hague Convention on Intercountry Adoption governs international adoptions between participating countries, but it covers only children under 16 at the time the petition is filed, with a narrow sibling exception.3U.S. Citizenship and Immigration Services. Hague Process Adults sit entirely outside its scope. None of the Hague accreditation requirements or safeguards apply, and the adoption is governed only by the domestic law of the state where you file.
Where Adult Adoption Is Legal
Nearly every U.S. state has a statute permitting adult adoption. Roughly two-thirds allow any adult to adopt any other adult with minimal restrictions. The remaining third impose conditions such as a minimum age gap between the parties, commonly 10 to 15 years, or evidence of a pre-existing relationship resembling a parent-child bond. A small number of states limit adult adoption to people between 18 and 21, but that is uncommon.
The adoptee’s home country adds a second layer. Some countries do not recognize adult adoption at all; others impose their own residency or consent requirements. A U.S. court can finalize the adoption under state law regardless of what the foreign country thinks. But if the adoptee later needs the adoption recognized where they were born, non-recognition can cause problems with property, name changes, or family status there. Check both the state statute and the home-country rules before filing.
What the Court Will Require
Consent
Adult adoption turns almost entirely on whether both parties agree. The adoptee provides written, usually notarized, consent. Courts may hold a brief hearing to confirm the consent was voluntary, but the inquiry is far lighter than for a child adoption. Most states do not require a home study, background check, or investigation into the adopter’s fitness.
Age and Relationship
The adoptee must be at least 18, or whatever the local age of majority is. Some states require the adopter to be older than the adoptee by a set number of years. Formalizing a stepparent-stepchild bond is common, and many states allow adoptions between people with no prior family tie at all. Some courts will still ask whether the adoption serves a legitimate purpose, largely to screen out adoptions designed only to manipulate inheritance or evade another law.
Residency and Jurisdiction
You file in the state and county where you live. Jurisdiction usually rests on the adopter’s residence, though some states also accept jurisdiction where the adoptee resides.4Child Welfare Information Gateway. Court Jurisdiction and Venue for Adoption Petitions The adoptee does not always need to be physically present in the U.S. for the state court process, though some courts require an appearance at a hearing.
The Court Process With Foreign Documents
You submit a petition to the appropriate court along with the adoptee’s written consent, identification, and any evidence the court requires about the relationship or the purpose of the adoption. Because the adoptee is from another country, expect to produce translated and apostilled foreign documents such as a birth certificate or national identity card.
Many courts handle adult adoptions without a contested hearing. The judge reviews the paperwork, may ask a few questions to confirm consent, and issues an adoption decree. A simple case can wrap up in a few weeks, though document authentication, court scheduling, and foreign paperwork requirements often stretch the timeline. Once the decree is issued, it creates a legal parent-child relationship under state law, and you can request an amended birth certificate from the vital records office of the state where the adoption was finalized.
What It Changes for Inheritance
An adoption decree creates the same legal parent-child relationship that exists between biological parents and children. Under state intestacy rules (the defaults that apply when someone dies without a will), the adopted adult can inherit from you just as a biological child would, and you can inherit from them.
Adoption also typically severs the legal parent-child relationship between the adoptee and their biological parents. In most states, that means the adoptee loses intestacy rights from the biological family. Some people do not anticipate this, especially when the adoptee remains close to biological relatives. A handful of states carve out exceptions for stepparent adoptions, preserving ties to the other biological parent’s family, but the general rule is a clean legal break.
Adult adoption can also disrupt estate plans created by third parties. If a trust or will leaves assets to someone’s “children” or “descendants,” an adopted adult may fall into that class and reduce what other beneficiaries receive. Existing heirs sometimes challenge these adoptions, arguing they were motivated by financial gain rather than a genuine family relationship. Courts can scrutinize adoptions that appear designed primarily to capture an inheritance, though the bar for undoing a finalized adoption is high.
Tax Consequences
No Adoption Tax Credit
The federal adoption tax credit does not apply to adult adoptions. To qualify, the adoptee must be under 18 or physically or mentally incapable of self-care.5Internal Revenue Service. Adoption Credit For 2026, the maximum credit for qualifying child adoptions is $17,670. It has no bearing on an adult adoption, so leave it out of the budget.
Claiming the Adoptee as a Dependent
You may be able to claim an adult adoptee as a dependent, but only under the “qualifying relative” rules. The adoptee must live with you for the entire year, have gross income below the annual threshold (currently $5,050), and receive more than half of their financial support from you.6Internal Revenue Service. Dependents Those requirements are hard to meet for a working adult, so this is realistic mainly when the adoptee is financially dependent and not earning much.
Gift Tax
Transferring significant assets to the adoptee after the adoption triggers the same gift tax rules as any other transfer. For 2026, you can give up to $19,000 per recipient per year without any gift tax reporting.7Internal Revenue Service. Frequently Asked Questions on Gift Taxes Anything above that eats into your lifetime exemption and requires a gift tax return. The adoption itself doesn’t trigger the tax, but large transfers that follow can. If meaningful assets are involved, working with a tax attorney before or shortly after the adoption is worth the cost.
What It Costs
Adult adoption is far cheaper than international child adoption, which can run tens of thousands of dollars. Court filing fees for an adult adoption petition generally range from about $100 to $400. Attorney fees vary, but a straightforward uncontested adult adoption handled by a family law attorney typically runs $1,000 to $3,000. Translation, authentication, and apostille services for foreign documents can add several hundred dollars more.
Because most states do not require a home study for adult adoptions, one of the larger expenses of child adoption disappears. Complications from foreign documents, contested issues, or separate immigration questions raise the total, but a simple uncontested case usually comes in well under $5,000.