In the United States, you legally stop being a child at 18 in most places. That is the age of majority in 47 states and Washington, D.C. Three states set it higher: 19 in Alabama and Nebraska, and 21 in Mississippi.1Cornell Law Institute. Age of Majority But adulthood in the law isn’t a single switch. Some adult rights arrive earlier, several don’t arrive until 21 or later, and a handful of parental obligations run well past the day you’re technically an adult.
What the Age of Majority Actually Means
The age of majority is the birthday when the law treats you as a full adult. You can sign contracts that bind you, make your own medical decisions, sue or be sued in your own name, and live independently without parental consent. You also become fully responsible for your own debts and actions.1Cornell Law Institute. Age of Majority
Reaching it doesn’t automatically hand you every adult privilege. Plenty of activities have their own age floors written into federal or state law, and those override the general threshold. A 19-year-old in Alabama has reached the age of majority but still can’t legally buy a beer.
What Changes at 18
Eighteen is the birthday that carries the most legal weight, even in the states that set majority higher.
Voting and Jury Duty
You can vote in all federal, state, and local elections at 18.2USAGov. Who Can and Cannot Vote About 21 states and D.C. let 17-year-olds vote in primaries if they’ll turn 18 by the general election.3National Conference of State Legislatures. Voting Age for Primary Elections Federal jury service also opens at 18, with U.S. citizenship and one year of residency in the judicial district required.4Office of the Law Revision Counsel. 28 US Code 1865 – Qualifications for Jury Service Most states use the same floor for state courts.
Contracts
Before the age of majority, contracts a minor signs are generally voidable, meaning the minor can back out. The main exception is contracts for necessities like food, clothing, and shelter, which courts will enforce against a minor. Once you reach majority, you have full contractual capacity and can’t escape a deal simply because of your age.
Selective Service
Nearly all male U.S. citizens and male immigrants must register with the Selective Service System within 30 days of their 18th birthday.5Selective Service System. Who Needs to Register The registration window runs through age 25. Failing to register makes you ineligible for federal student financial aid, and knowing failure is a federal crime punishable by up to five years in prison or a fine up to $10,000.6Office of the Law Revision Counsel. 50 USC 3811 – Offenses and Penalties
Adult Criminal Court
In most states, juvenile court jurisdiction stops at 17. From 18, criminal charges are handled in adult court by default. Serious offenses can also pull younger teenagers into adult court through state transfer mechanisms.7Office of Juvenile Justice and Delinquency Prevention. Age Boundaries of the Juvenile Justice System
Adult Things You Still Can’t Do at 18
Several activities have age floors above the age of majority.
Alcohol. The legal purchase age is 21 in every state. Federal law withholds a portion of highway funding from any state that allows sales below 21,8Office of the Law Revision Counsel. 23 USC 158 – National Minimum Drinking Age and every state has complied since the late 1980s.9Centers for Disease Control and Prevention. Why a Minimum Legal Drinking Age of 21 Works
Tobacco and nicotine. Since December 2019, federal law has prohibited retailers from selling any tobacco or nicotine product, including e-cigarettes, to anyone under 21.10U.S. Food and Drug Administration. Tobacco 21 It’s a nationwide floor, not a state option.11Centers for Disease Control and Prevention. STATE System Minimum Legal Sales Age Laws for Tobacco Products Fact Sheet
Firearms. A federally licensed dealer can sell a rifle or shotgun at 18, but handguns require the buyer to be at least 21.12Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Private sales follow different rules, and many states add restrictions on top.
Gambling. Casinos and sports betting operations generally require 21. State lotteries, bingo, and pari-mutuel wagering usually allow 18. The rules vary by state and by type of gambling, and tribal gaming operations may set their own thresholds. Check your state before you wager.
Rights That Arrive Before 18
Work
Federal law sets 14 as the minimum age for most non-agricultural work, with tight hour and time-of-day limits for 14- and 15-year-olds.13U.S. Department of Labor. Age Requirements14U.S. Department of Labor. Fact Sheet 43 – Child Labor Provisions of the Fair Labor Standards Act for Nonagricultural Occupations At 16, those caps disappear, but jobs the Department of Labor has declared hazardous, such as operating power-driven machinery, mining, roofing, or handling explosives, remain off-limits until 18.15eCFR. Child Labor Regulations, Orders and Statements of Interpretation
Driving
Most states issue learner’s permits around 15 or 16, then phase in full privileges through a graduated system. Expect a learner’s permit at 15 or 16, a restricted license at 16 or 17 with passenger and nighttime limits, and a full license somewhere between 17 and 18. A handful of states hold unrestricted licenses until 18.
Sexual Consent and Marriage
The age at which a minor can legally consent to sexual activity ranges from 16 to 18 depending on the state. A majority of states set it at 16, a smaller group at 17, and about a dozen at 18. Many states have close-in-age exceptions that reduce or eliminate penalties when both people are close in age.
Marriage is more complicated. Every state sets the general marriage age at 18 or the state’s age of majority, but most still allow exceptions with parental consent, a judge’s approval, or both. About 16 states have banned marriage under 18 outright. A few states have no statutory minimum when a court approves, though the recent trend has moved toward raising minimums and closing loopholes.
When Parental Obligations End
Reaching the age of majority ends most parental obligations by default, but several financial and benefit thresholds run past it.
Child Support
Child support obligations typically end at the age of majority. Many states extend support for a child still in high school full-time, usually until graduation or age 19, whichever comes first. Support may continue indefinitely for an adult child with a significant physical or mental disability who cannot self-support; this exception exists in most states and has no age cutoff.
Support doesn’t end automatically when a child turns 18. In many states, the paying parent must file a motion to terminate the order. Until a court modifies or terminates it, the obligation keeps running and arrears keep accumulating.
Health Insurance Through Age 26
Under the Affordable Care Act, any health plan offering dependent coverage must make it available until the child turns 26. The insurer can’t deny it based on marital status, student status, employment, financial independence, or eligibility for other coverage.16eCFR. 45 CFR 147.120 – Eligibility of Children Until at Least Age 26 Losing that access at 26 pushes young adults onto employer coverage, a marketplace plan, or Medicaid.
Tax Dependency
For federal income tax, a parent can claim a qualifying child under 19 at year-end. That extends to under 24 if the child is a full-time student for at least five months of the year. A permanently and totally disabled child can be claimed at any age.17Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined The child must also be younger than the taxpayer (or the taxpayer’s spouse on a joint return) and meet residency and support tests.18Internal Revenue Service. Qualifying Child Rules
Social Security Benefits
Children receiving Social Security on a parent’s record, whether survivor or dependent benefits, generally lose them at 18. If the child is still a full-time student in elementary or secondary school (not college), benefits can continue until graduation or two months after turning 19, whichever is earlier. Benefits continue indefinitely if the child has a disability that began before age 22.19Social Security Administration. Benefits for Children
Custodial Accounts
Money held in a custodial account under the Uniform Transfers to Minors Act or Uniform Gifts to Minors Act must be turned over to the beneficiary at the transfer age set by state law. In many states that age is 21 for the most common gifts; some states use 18, and a few allow extensions to 25.20Social Security Administration. The Legal Age of Majority for Uniform Transfer to Minors Act Once transferred, the former minor has full control with no restrictions on how they spend the money. Parents who want continuing control should consider a trust instead.
Emancipation: Ending Childhood Early
Emancipation is a legal process that gives a minor some or all adult rights before the age of majority. It’s uncommon and not an escape hatch for teenagers unhappy at home. Courts treat it as a serious change that permanently alters the parent-child relationship.
The most common paths are marriage, enlisting in the military, or a court order. For court-ordered emancipation, a minor files a petition in family or probate court, must show they can support themselves financially and manage their own affairs, and must persuade the court that emancipation serves their best interests. The minor’s age, physical and mental health, and the parents’ ability to provide basic support all factor in. Most states with a formal process require the petitioner to be at least 16, though this varies. Filing fees range from nothing to a few hundred dollars.
Emancipation does not grant every adult right. An emancipated 16-year-old can sign a lease and open a bank account, but still can’t buy alcohol, vote, or do anything else governed by a separate age-specific statute. Those thresholds don’t bend for emancipation.