Adult adoption in California lets one adult become the legal parent of another adult through a written agreement approved by a superior court judge. The process is short compared with child adoption: no home study, no termination of anyone’s existing parental rights, a $20 filing fee, and a single hearing. The legal effects, however, are lasting. The adoptee becomes the adoptive parent’s legal child for inheritance and next-of-kin purposes, and in most cases loses those same rights with respect to biological parents.1California Legislative Information. California Code FAM 9300 – Adoption of Adults and Married Minors
Who Qualifies
Family Code 9300 allows any adult to adopt another adult, including a stepparent adopting an adult stepchild. A few conditions apply.
The adoptee must be younger than the adopting parent. Family Code 9320 makes this a statutory requirement, not a matter of judicial preference.2California Legislative Information. California Code Family Code – Procedure for Adult Adoption There is no set minimum gap, but when the difference is small, a judge will look harder at whether the relationship actually reflects a parent-child dynamic. You cannot adopt your own spouse; the statute rules that out.
If the adoptee is married or has a registered domestic partner, that spouse or partner must consent. The same goes for the adopting parent’s spouse if they have one. The rule exists to prevent surprises in property and inheritance for the people already tied to each party.
How the Process Works
The core document is a written adoption agreement. Under Family Code 9320, both parties sign a statement that they voluntarily agree to assume the legal relationship of parent and child, with all the rights and responsibilities that come with it. Because the adoptee is an adult, participation is fully voluntary, and the agreement itself is proof of consent. If a judge suspects coercion or that either party doesn’t understand the effect of what they are signing, the petition will be denied.
You file the petition in the superior court of the county where either the adopting parent or the adoptee lives.3California Courts. Adult Adoption in California Family Code 9321 requires the petition to state:
- How long the parties have known each other and the nature of their relationship
- Whether they are related by blood, and if so, how
- The reason for the adoption
- Why the adoption is in the best interest of both parties and the public
- Names and addresses of the adoptee’s living birth parents and any adult children
- Whether the adopting parent, or their spouse, has previously adopted another adult
The primary form is the Adoption Request (ADOPT-200), available from the California courts.4Judicial Branch of California. Adoption Request (ADOPT-200) Along with it you’ll file the proposed adoption agreement and a proposed order. Some counties ask for additional documents; check with the clerk before filing. The filing fee is $20, and a fee waiver is available for people who receive public benefits, earn below a set income threshold, or cannot pay the fee and still meet their basic needs.
Once filed, the clerk sets a hearing. Both the adopting parent and the adoptee must appear in person unless the court allows otherwise. The judge may question the parties about their relationship and reasons for the adoption. Under Family Code 9328, the judge approves the adoption only if satisfied that it serves the best interests of both parties and the public. The court can consider any written or oral evidence and is not bound by the usual rules of evidence. Unlike a child adoption, no investigation or agency report is required, though the court can order one. Timing varies by county from a few weeks to a few months.
What Changes for Inheritance
Inheritance is the most common reason people pursue adult adoption in California, and it is where the stakes are highest.
Under Probate Code 6450, a parent-child relationship exists between an adopted person and the adoptive parent for purposes of intestate succession. If the adoptive parent dies without a will, the adult adoptee inherits as a biological child would.5California Legislative Information. California Code Probate Code 6450 – Parent and Child Relationship
The part people often miss is on the other side. Under Probate Code 6451, adoption generally severs the inheritance relationship with the adoptee’s biological parents; the adoptee loses the right to inherit from birth parents, and birth parents lose the right to inherit from the adoptee.6California Legislative Information. California Code Probate Code 6451 – Natural Parent and Child Relationship There are narrow exceptions. The inheritance link with a biological parent survives if the biological parent and the adoptee previously lived together as parent and child, and the adoption was either by a stepparent or occurred after the biological parent’s death. Outside those specific facts, the severance is complete.
Anyone considering adult adoption in California should map out both sides of the inheritance picture before going to court, ideally with an estate planning attorney. An adoptee who assumed they would inherit from both a biological parent and an adoptive parent can end up cut off from the biological parent’s estate.
Other Rights and Benefits That Do and Don’t Follow
Adult adoption changes several practical relationships beyond inheritance.
Health Insurance
Under the Affordable Care Act, health plans that cover dependents must let children stay on a parent’s plan until age 26, whether the child is adopted, biological, or a stepchild.7HealthCare.gov. Health Insurance Coverage For Children and Young Adults Under 26 An adoptee under 26 can be added to the adoptive parent’s plan. After 26, coverage depends on the plan and state rules; there is no federal right to remain on a parent’s insurance past that point.
Family and Medical Leave
The Family and Medical Leave Act includes adopted children in its definition of “son or daughter,” but for adult children age 18 and older, FMLA leave is available only if the adult child has a disability that makes them incapable of self-care. The condition must substantially limit a major life activity, and the adult child must need help with at least three daily tasks such as bathing, dressing, cooking, or managing finances.8U.S. Department of Labor. Questions and Answers Concerning the Use of FMLA Leave to Care for a Son or Daughter Age 18 or Older FMLA leave to care for a healthy adult adoptee is not available.
Next of Kin and Medical Decisions
The adoption establishes legal next-of-kin status between the parties. Depending on circumstances, the adoptee may gain authority to make medical decisions for the adoptive parent during incapacity, and vice versa. Social Security survivor benefits and benefits tied to the adoptive parent’s employment or veteran status may also be affected, though each program has its own qualifying rules.
Name Change
A name change does not happen automatically. If the adoptee wants to take the adoptive parent’s last name, that generally requires a separate petition under Code of Civil Procedure 1276, filed in the superior court where the adoptee lives.9California Legislative Information. California Code of Civil Procedure 1276 – Application for Change of Name
What Adult Adoption Cannot Do
Two areas are commonly assumed to follow from adoption but do not.
Immigration. Adopting an adult in California state court creates no immigration eligibility. Under federal law, an adopted person qualifies as a “child” for immigration purposes only if adopted before age 16 and after living with the adoptive parent for at least two years.10U.S. Department of State. 9 FAM 502.3 – Classification of Immigrants Under INA A U.S. citizen can petition for an adopted “son or daughter” now over 21 only if that person previously met the child definition, which means the adoption had to occur before age 16.11U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 5, Part E, Chapter 2 – Eligibility USCIS has stated this directly: adult adoptees who did not meet the child definition under immigration law gain no path to a green card or citizenship through adoption.12U.S. Citizenship and Immigration Services. Adult Adoptees and U.S. Citizenship Encouraging someone to enter or remain in the United States illegally based on promises about adult adoption can lead to federal criminal charges carrying up to five years in prison, or ten years if done for financial gain.
Adoption Tax Credit. The federal Adoption Tax Credit is limited to adopting a child who is either under 18 or physically or mentally unable to care for themselves.13Internal Revenue Service. Adoption Credit Adopting a healthy adult gives no adoption-related tax benefit. Claiming the adult adoptee as a dependent is possible only if the ordinary dependent rules are met: living with you, income below the threshold, and relying on you for more than half of their financial support.
Can It Be Undone?
Treat adult adoption in California as permanent. There is no dedicated reversal statute for adult adoptions. The annulment procedure in Family Code 9100 is written for child adoptions where the child shows evidence of a developmental disability or mental illness that existed before the adoption and was not disclosed, and it must be filed within five years of the adoption order. For adult adoptions, a court may in rare cases vacate the order on grounds such as fraud or duress under its general equitable powers, but that outcome is exceptional. Anyone weighing the decision should assume the adoption cannot be undone and decide accordingly.