The legal age of marriage in the US is 18 in every state except Nebraska, where it’s 19, and Mississippi, where full legal adulthood is 21. Below those ages, the rules split: around 21 states let 16- and 17-year-olds marry with a parent’s signature, several require a judge’s approval for anyone younger, four states still have no minimum age at all, and 16 states plus Washington, D.C. have eliminated every exception and set a firm 18 floor.
The 18 Default
Once you turn 18, you can apply for a marriage license on your own. No parent, guardian, or judge has to sign off. The law treats you as a legal adult capable of entering a binding contract and all the financial consequences that follow: joint debt, shared property, spousal support.
Two states shift the number. Nebraska’s age of majority is 19, so independent marriage tracks that age. Mississippi sets legal adulthood at 21, though separate provisions let younger residents marry under certain conditions. Everywhere else, 18 is the universal starting line.
There is no federal marriage age law. The Supreme Court has recognized marriage as a fundamental liberty, but the actual license requirements are a state matter. A bill called the Child Marriage Prevention Act was introduced in Congress in 2024 and would have barred the use of federal property for marriages involving anyone under 18, but it stalled in committee and never became law.1Congress.gov. S.4990 – Child Marriage Prevention Act of 2024
Marrying at 16 or 17 With Parental Consent
Roughly 21 states let a 16- or 17-year-old marry if a parent or legal guardian consents. The parent usually has to appear in person at the clerk’s office or provide a notarized statement. Some jurisdictions accept one parent’s signature; others want both unless a custody order gives one parent sole authority. If a legal guardian is signing instead of a parent, court-issued guardianship paperwork generally has to be shown.
The theory is that the family acts as a protective check. Critics counter that the people providing consent are sometimes the same people pressuring the minor into the marriage, which is a large part of what has fueled recent reform.
Judicial Approval for Younger Minors
When a minor is under 16, or when a state wants more than a parent’s signature, a judge decides. The court looks at whether the marriage is in the minor’s best interests and weighs factors like maturity, financial stability, and signs of coercion. A judge may interview the minor privately, appoint an independent representative, or order premarital counseling before approving.
Historically, pregnancy or an existing child was the most common trigger for these exceptions, and courts sometimes approved marriages for children as young as 13 or 14 on that basis. That practice has mostly fallen out of favor. Most states that have reformed their laws over the past decade specifically removed pregnancy as a qualifying exception, though a small number still allow it to lower the age floor.
States With No Minimum Age
Four states still have no absolute minimum age for marriage: California, Mississippi, New Mexico, and Oklahoma. In theory, a child of any age could marry there with the right combination of parental consent and judicial approval. The absence of a floor doesn’t mean these marriages happen often, but the statute books contain no hard line against them. Advocacy groups have pushed for change in each of these states with mixed results.
States That Have Banned Marriage Under 18
The biggest shift of the past decade is the growing list of states that have eliminated every exception below 18. Delaware and New Jersey went first in 2018. By the end of 2025, at least 16 states plus Washington, D.C., the U.S. Virgin Islands, and American Samoa had set a firm 18 floor with no carve-outs for parental consent, judicial approval, or pregnancy. Oregon’s ban takes effect in 2026.
The states with a full ban are Delaware, New Jersey, Pennsylvania, Minnesota, Rhode Island, New York, Massachusetts, Vermont, Connecticut, Michigan, Washington, Virginia, New Hampshire, Missouri, Maine, and Oregon. Several more have tightened their laws without going all the way to a complete ban, raising the minimum age or layering on judicial oversight.
The reasoning behind the bans is practical. A married minor often cannot file for divorce on their own, hire an attorney, or check into a domestic violence shelter without an adult’s involvement. Giving someone the responsibilities of marriage without the legal tools to exit a bad one creates a trap. Aligning the marriage age with voting, contract-signing, and other major legal acts closes that gap.
What Marriage Does to a Minor’s Legal Status
In most states, getting married automatically emancipates a minor. The minor gains the legal capacity to act as an adult in many respects: signing contracts, consenting to medical treatment, establishing a residence, managing finances. Parents are usually released from the obligation to provide financial support.
Emancipation through marriage does not override every age-restricted law. A married 16-year-old still cannot buy alcohol, buy tobacco, or vote. And in states that don’t formally emancipate married minors by statute, the minor can end up in a gray zone: legally married, but without the authority to manage what the marriage requires.
Leaving the Marriage Is Harder Than Entering It
Reform advocates point to a specific legal catch. Filing for divorce means initiating a lawsuit, which minors generally can’t do on their own. Hiring an attorney means signing a retainer, which is a contract, and contracts signed by minors may not be enforceable. Domestic violence shelters often require residents to be 18 or have a guardian involved. A minor who needs out may have to rely on the same family members who signed them in.
Tax Impact for the Minor’s Parents
If your minor child marries and files a joint tax return with their spouse, you generally lose the ability to claim that child as a dependent. The IRS applies a joint return test that disqualifies a married child who files jointly, with one narrow exception: if the child and their spouse file jointly only to claim a refund of withheld or estimated taxes and neither spouse would otherwise owe any tax, you can still claim the child as a dependent. If the joint return claims any credit beyond that refund, the exception doesn’t apply.2Internal Revenue Service. Publication 501 (2025), Dependents, Standard Deduction, and Filing Information
Marriages That Cross State Lines
Most states follow the place-of-celebration rule: if a marriage was valid where it was performed, other states will recognize it. A couple who legally married at 16 in a state that permitted it with parental consent would generally keep that marriage recognized after moving to a state where 18 is the absolute minimum. The rule isn’t absolute. A state can refuse to recognize an out-of-state marriage that violates its own strong public policy, and as more states adopt firm 18-and-over rules, those questions are likely to get tested more often.
Immigration Recognition
USCIS will recognize a marriage involving a minor for immigration purposes if the marriage was legal where it took place and is consistent with the law or public policy of the state where the couple lives or plans to live. The agency looks closely at whether the marriage was lawful, bona fide, and entered with the minor’s full and free consent.3USCIS. USCIS Policy Manual Volume 6, Part B, Chapter 6 – Spouses
There is no minimum age to file or to be the beneficiary of a spousal petition. But anyone signing the Affidavit of Support must be at least 18. Because the petitioning spouse typically signs that affidavit, a petitioner under 18 effectively cannot complete the process, and USCIS will deny the adjustment application.3USCIS. USCIS Policy Manual Volume 6, Part B, Chapter 6 – Spouses
Annulling an Underage Marriage
An underage marriage performed without proper consent is generally voidable rather than void. The difference matters. A void marriage is treated as legally invalid from the start and needs no court action to undo. A voidable marriage is treated as valid until someone successfully challenges it. Most underage marriages fall into the voidable category, which means they stay legally binding unless the minor or a parent acts.
The minor who married underage can typically file for annulment within a set number of years after reaching the age of consent. A parent, guardian, or person with legal responsibility can also file on the minor’s behalf, usually at any time before the minor reaches adulthood. If no one acts within the window, the marriage remains valid. The exact deadlines and procedures vary by state, so anyone considering a challenge should check local law quickly.