When you turn 18 in the United States, you become a legal adult: you can vote, sign binding contracts, control your own medical care and school records, enlist in the military without a parent’s signature, and face criminal charges in adult court. What happens when you turn 18 is both broader and narrower than most people assume. Parental authority largely ends, but health insurance eligibility runs to 26, alcohol and tobacco purchases wait until 21, and a few paperwork steps, such as Selective Service registration for men, carry real consequences if you skip them.
You Control Your Own Medical Care and Records
At 18 you decide which treatments to accept or decline, choose your own doctors, and access your own medical records. HIPAA privacy rules then stop healthcare providers from sharing your medical information with your parents unless you give explicit consent. That applies even if you are still on their insurance plan.
The shift catches families off guard during emergencies. If you are in a serious accident and cannot communicate, your parents have no automatic legal right to discuss your condition with doctors or make treatment decisions for you. The day before your birthday they could do both without a second thought. Afterward, hospitals follow HIPAA unless you have signed documents authorizing someone to act for you.
Educational Records Under FERPA
The Family Educational Rights and Privacy Act transfers control of your school records from your parents to you once you turn 18 or enroll in a postsecondary institution, whichever comes first.1Office of the Law Revision Counsel. 20 U.S.C. 1232g – Family Educational and Privacy Rights Schools cannot release your transcripts, grades, or disciplinary records to your parents without your written permission. Many colleges offer FERPA waiver forms that let you voluntarily grant parents access, but signing one is your choice.
Why You Need Estate Planning Documents Now
This is the step most 18-year-olds skip, and it may be the most important one on the list. The same privacy laws that protect your autonomy also put a wall between you and the people most likely to help in a crisis. Two inexpensive documents handle the problem before it becomes an emergency.
A healthcare power of attorney, sometimes called a healthcare proxy, designates someone (often a parent) to make medical decisions if you are unconscious or otherwise unable to communicate. Without one, your family may need to petition a court for guardianship just to talk to your doctors, a process that typically takes weeks and can cost thousands of dollars. A durable financial power of attorney does the same thing for financial matters, letting a trusted person pay your bills, manage your bank accounts, or handle insurance claims if you are incapacitated.
Both documents are straightforward to create. Many states offer free or low-cost statutory forms, and recording fees are typically modest. Sign them before you need them. By definition you cannot sign a power of attorney after you have lost the ability to make decisions.
Parental Authority Ends
Your parents lose legal custody the moment you turn 18. They can no longer make decisions about where you live, what medical care you receive, or how your education proceeds. Courts will not enforce a parent’s wishes over an adult child’s autonomy, and visitation orders from custody arrangements expire.
The legal obligation for parents to financially support you generally ends at 18. A few states extend the duty to 19 or through high school graduation, and courts in many states can order continued support for an adult child with a disability who cannot live independently. The baseline rule, though, is that parental support is no longer guaranteed.
Health insurance is the big exception to the “you are on your own” theme. Under the Affordable Care Act, health plans that offer dependent coverage must keep you eligible until you turn 26, regardless of whether you still live with your parents, whether they claim you as a tax dependent, or whether you are a student.2Centers for Medicare and Medicaid Services. Young Adults and the Affordable Care Act You are not required to stay on a parent’s plan, but it is often the most affordable option through your early twenties.
Contracts and Credit Become Binding
Before 18, most contracts you sign are voidable: you can walk away from them, and the other party has limited recourse. At 18 that protection disappears. Leases, car loans, cell phone agreements, and gym memberships all become binding, and breaking them has real financial consequences.
You can open a bank account without a parent or guardian co-signing. You can also apply for credit cards, but federal law adds a hurdle for anyone under 21. You must either show independent income sufficient to make payments or have a cosigner who is at least 21.3Office of the Law Revision Counsel. 15 U.S.C. 1637 – Open End Consumer Credit Plans Many major card issuers have stopped allowing cosigners, which in practice means you need verifiable income to get approved on your own.
Student and auto loans also become available. Federal student loans through FAFSA do not require a credit check for most borrowers, but private lenders will look at a credit history that at 18 is likely nonexistent. Building credit early through a secured card or by becoming an authorized user on a parent’s account makes a noticeable difference when you later apply for housing or a car loan.
Adult Court and Your Juvenile Record
Crimes committed after your 18th birthday are handled in adult court, not juvenile court. In 44 states, 17 is the upper age limit for juvenile jurisdiction, so the switch happens the moment you turn 18. Adult court means adult sentencing: longer potential prison terms, public criminal records, and incarceration in adult facilities rather than juvenile detention.
Your juvenile record may move the other direction. About half the states now have laws that automatically seal or expunge certain juvenile records, often triggered by the person’s 18th birthday or a short waiting period afterward. Some states seal records within 30 days of turning 18; others require that probation or court supervision has ended first. If your state does not seal records automatically, you typically need to petition the court yourself.
Civic Duties: Voting, Jury Duty, Selective Service
The 26th Amendment guarantees that no citizen 18 or older can be denied the right to vote on account of age.4Congress.gov. Constitution of the United States, Amendment 26 That covers federal, state, and local elections. Registration is available in every state, and many states let you register online or at the DMV.
Jury duty kicks in at 18 as well. Federal courts require jurors to be at least 18, a U.S. citizen, a resident of the judicial district for at least one year, and proficient enough in English to fill out the qualification form.5Office of the Law Revision Counsel. 28 U.S.C. 1865 – Qualifications for Jury Service State courts have similar requirements. Ignoring a summons can lead to fines or a contempt finding.
Every male U.S. citizen and male immigrant living in the United States must register with the Selective Service within 30 days of turning 18.6Office of the Law Revision Counsel. 50 U.S.C. 3802 – Registration The requirement runs through age 25. As of 2026, women are not required to register. Skipping registration has consequences people often don’t learn about until they apply for something: you become ineligible for federal student financial aid, federal job training programs, most federal employment, and, for immigrant men, U.S. citizenship. Failure to register is technically a felony punishable by up to $250,000 in fines and five years in prison, though prosecutions are rare.7Selective Service System. Benefits and Penalties The financial aid consequence alone catches people off guard when they try to file the FAFSA and get flagged.
Work and Taxes
Federal child labor rules under the Fair Labor Standards Act restrict both the hours minors can work and the jobs they can hold. Those restrictions disappear at 18.8U.S. Department of Labor. Fact Sheet 43 – Child Labor Provisions of the FLSA for Nonagricultural Occupations Jobs the Department of Labor has declared hazardous, such as operating certain heavy machinery, roofing, excavation, and work with explosives, open up, and you can work any shift for any number of hours.
One thing that does not change at 18 is the youth sub-minimum wage. Federal law allows employers to pay as little as $4.25 per hour during your first 90 calendar days of employment if you are under 20.9U.S. Department of Labor. Minimum Wage After that 90-day window, or once you turn 20, you must be paid at least the full federal minimum wage of $7.25 per hour, or your state’s minimum wage if it is higher.
Turning 18 does not automatically trigger a tax obligation; earning income does. If you are single and under 65 with gross income of at least $15,750 for tax year 2025, you are required to file a federal return.10Internal Revenue Service. Publication 501 – Dependents, Standard Deduction, and Filing Information That threshold applies at any age. What changes at 18 is that you are now personally responsible for filing and paying any tax owed, even if your parents still claim you as a dependent.
Other Rights You Pick Up at 18
- Military enlistment in any branch without parental consent. At 17 you need a parent’s signature.11Today’s Military. Military Requirements for Joining
- Buying rifles and shotguns from licensed dealers. Handgun sales from licensed dealers still require you to be at least 21.12Office of the Law Revision Counsel. 18 U.S.C. 922 – Unlawful Acts
- Marrying without parental or judicial consent in most states.
- Registering as an organ donor on your own. Once you are 18 and signed up through your state registry, your consent is legally binding, and no one, including your parents, can override it.13Organ Donation FAQ | organdonor.gov. Organ Donation FAQ
- Applying for a passport as an adult using Form DS-11. A passport book costs $130 plus a $35 facility fee for a first-time in-person application, and adult passports are valid for 10 years rather than the 5-year validity for passports issued to children under 16.14Travel.State.Gov. Apply for Your Adult Passport
- Suing and being sued in your own name. As a minor someone had to act for you through a legal guardian or “next friend.” At 18 you are a party in your own right.
What You Still Cannot Do at 18
Turning 18 does not unlock everything. Several significant age restrictions sit at 21, and confusing them with the age of majority leads to real legal trouble.
You cannot legally buy alcohol anywhere in the United States. The National Minimum Drinking Age Act effectively requires every state to set 21 as the minimum purchase and public possession age for alcoholic beverages by tying compliance to federal highway funding.15NIAAA Alcohol Policy Information System. The 1984 National Minimum Drinking Age Act Every state complies.
You cannot buy tobacco products, including cigarettes, cigars, and vaping products. Federal law raised the minimum purchase age from 18 to 21 in December 2019.16U.S. Food and Drug Administration. FDA Issues Final Rule Increasing the Minimum Age for Certain Restrictions on Tobacco Sales The change is recent enough that it still surprises some 18-year-olds.
Handgun purchases from licensed dealers also require you to be 21.12Office of the Law Revision Counsel. 18 U.S.C. 922 – Unlawful Acts And while you can apply for a credit card at 18, the under-21 income or cosigner rule above means approval is not automatic. Car rental companies typically impose a minimum age of 20 to 25, with surcharges for younger renters, though this is company policy rather than federal law.