Legal Ages & Milestones

Age of Majority by State: What Changes When You Turn 18?

Turning 18 is the most significant legal milestone in American life. It changes your rights, your obligations, and your relationship with virtually every institution — from healthcare to housing to the criminal justice system. Here is exactly what shifts when the clock strikes midnight on your 18th birthday.

Updated March 2026 · 13 min read

State Exceptions — Age of Majority Above 18

In most states, the age of majority is 18. Three jurisdictions differ:

Alabama (age 19): Full age of majority is 19. Federal rights (voting, military) still trigger at 18, but state contract law and parental authority persist until 19.
Nebraska (age 19): Age of majority is 19. Same federal/state split as Alabama.
Mississippi (age 21): Highest age of majority in the US. However, federal rights (voting, military) apply at 18. State-level contract, custody, and civil rights persist until 21.

Federal vs. State Rights at 18

Some rights you gain at 18 are set by federal law and apply identically in all 50 states. Others are governed by state law and may vary — or may not activate until the state's age of majority, which is higher in Alabama (19), Nebraska (19), and Mississippi (21).

For example, the right to vote is protected by the 26th Amendment to the US Constitution, which prohibits states from denying voting rights to citizens 18 and older. This applies in all states including those with a higher state age of majority. Military enlistment without parental consent is similarly federal. But the ability to sign a binding lease or file a lawsuit independently is governed by state law and may not apply until your state's age of majority.

Things You Can (and Must) Do at 18

Civic & Political

Vote in federal, state, and local elections

Federal requirement under 26th Amendment.

Federal

Serve on a jury (in most states)

Jury eligibility varies slightly by jurisdiction.

Run for most state and local offices

US House requires 25, US Senate 30, President 35.

Sign a petition or legal document independently

Legal & Contracts

Sign legally binding contracts

The age of majority governs this in your state.

Sue and be sued in your own name

No guardian ad litem required.

Make a will

Some states require 18, others allow younger.

Be prosecuted as an adult in criminal court

Exceptions exist for serious crimes at younger ages in many states.

Serve on a jury

Medical & Personal

Consent to your own medical treatment

Replaces parental consent requirement.

Access your own medical records (HIPAA)

Parents lose automatic access to your records at 18.

Federal

Make end-of-life / advance directive decisions

Living will and healthcare proxy require age of majority.

Donate blood (without parental consent)

Many donation centers require 17+ for this.

Get a tattoo or piercing without parental consent (most states)

Financial

Open a bank account independently (no custodian)

Apply for credit cards in your own name

Cards require 18+; first card often needs a co-signer or secured deposit.

Apply for student loans independently

FAFSA requires independent status or parental info.

Federal

Invest in stocks and securities

Brokerage accounts can be opened at 18.

Be named as a beneficiary directly (for most accounts)

Enter binding financial contracts (loans, leases)

Housing & Independence

Sign a lease without parental co-signer (legally)

Landlords may still require co-signers for financial reasons.

Live independently without risk of being reported as a runaway

Apply for HUD housing assistance independently

Federal

Military & Government

Enlist in the military without parental consent

Parental consent required for 17-year-olds.

Federal

Required to register with Selective Service (men)

Registration required within 30 days of 18th birthday.

Federal

Apply for a passport without parental consent

Under-18 passports require parental signature.

Federal

What Does NOT Change at 18

Eighteen is a major threshold, but it is not the final one. Several significant legal milestones come later:

Right / PrivilegeMinimum Age
Purchase alcohol21
Purchase tobacco, nicotine, vaping products21
Purchase a handgun from a licensed dealer21
Rent a car (most companies)21
Run for US House of Representatives25
Run for US Senate30
Run for US President35
Full Social Security retirement benefits (full retirement age)66–67
Medicare eligibility (standard)65
Required minimum distributions from retirement accounts73

18 and the Criminal Justice System

Turning 18 has significant implications for how the legal system treats you if you are accused of a crime:

Adult Criminal Court

Before 18, you are typically handled in juvenile court, which focuses on rehabilitation and keeps records sealed or expunged. At 18, you are processed in adult criminal court, with a public record, potential prison sentence, and permanent consequences for employment, housing, and voting rights (in some states).

The Age 18–25 "Young Adult" Gap

Neuroscience research shows that the prefrontal cortex — the part of the brain governing impulse control and long-term decision-making — does not fully mature until around age 25. This has influenced some states and courts to create "young adult" courts or apply mitigating factors in sentencing for defendants 18–24. This is an evolving area of law.

Prior Juvenile Record

Juvenile records in most states are sealed when the person turns 18. This means they do not appear in standard background checks and cannot be used against you in most adult proceedings. However, serious felony convictions from the juvenile system can sometimes be unsealed by a court, and some employers (especially those working with children or in security) may be granted access.

Practical Steps to Take When You Turn 18

1.

Register to vote

Register at vote.gov in under 5 minutes. Deadlines vary by state — register before your first election.

2.

Register with Selective Service (men)

Required by federal law within 30 days of your 18th birthday. Register at sss.gov.

3.

Get your own health insurance or stay on parents'

You can stay on parents' insurance until 26 under the ACA, but check if coverage still works in your area.

4.

Open a bank account in your own name

You no longer need a parent as a joint account holder. Consider a checking account and a secured credit card to start building credit.

5.

Review your HIPAA status with healthcare providers

Decide whether to give parents access to your medical records. Sign a HIPAA release if you want them to remain in the loop.

6.

Establish power of attorney documents if needed

Consider a healthcare proxy and financial power of attorney for emergencies — especially if you are heading to college.

7.

Review your credit report

Visit annualcreditreport.com to check if you have any credit history and verify there is no identity fraud in your name.

Frequently Asked Questions

Do my parents automatically lose access to my medical records and college grades when I turn 18?

Yes — with important caveats. Under HIPAA (federal health privacy law), healthcare providers can no longer share your medical information with your parents without your written consent once you turn 18. Under FERPA (federal education privacy law), your college or university can no longer share your grades, disciplinary records, or financial aid information with your parents without your written permission. Many students choose to sign FERPA release forms if they want their parents to remain informed. Your parents lose this access automatically on your 18th birthday.

Can my parents still claim me as a dependent on their taxes after I turn 18?

Turning 18 does not automatically end your parents' ability to claim you as a dependent. The IRS uses a multi-factor test: you can be claimed as a 'qualifying child' through age 18 (or 23 if a full-time student) if you live with your parents for more than half the year and your parents provide more than half your financial support. Simply turning 18 does not break this — only moving out and becoming financially self-sufficient does.

What happens with mandatory Selective Service registration?

Male US citizens and most male immigrants who are between 18 and 25 are required by federal law to register with the Selective Service System. Registration is required within 30 days of your 18th birthday. Failure to register can have significant consequences: you may be ineligible for federal student aid, federal job training programs, US citizenship (for immigrants), and some federal employment. Registration is done online at sss.gov and takes minutes.

Can I be tried as an adult in criminal court before I turn 18?

Yes. While the default in the US juvenile justice system is to treat offenders under 18 as juveniles, all states allow (and some mandate) that juveniles be tried as adults for certain serious offenses. The threshold varies by state — some states allow transfer to adult court as young as 12 or 13 for homicide charges. In about a dozen states, 17-year-olds are automatically prosecuted in adult court regardless of the offense. The age of majority as an adult criminal defendant is a separate question from the civil age of majority.

Does turning 18 affect my driver's license?

In most states, 18 is when the restrictions of a graduated driver's license (GDL) system lift entirely — allowing unrestricted driving hours and full passenger capacity. However, your physical license may not change at 18; the restrictions simply no longer apply under state law. Check your state's DMV for the specific GDL stage timelines.

Can I buy tobacco and nicotine products at 18?

No. Federal law (the Tobacco 21 law, enacted December 2019) raised the minimum age to purchase tobacco products, cigarettes, e-cigarettes, and vaping products to 21 nationwide. This federal standard preempts state law — even states that previously had an 18 minimum must comply. There are no exceptions for military members. The minimum purchase age for all tobacco products in the US is 21.

What about buying a gun at 18?

Federal law prohibits federally licensed dealers from selling handguns to anyone under 21, and long guns (rifles, shotguns) to anyone under 18. However, federal law permits private sales (not through a licensed dealer) of long guns to 18-year-olds in states that do not impose additional restrictions. Many states have raised their own minimum handgun purchase ages to 21 for all sales, and some states prohibit long gun private sales to under-21 buyers. This is a rapidly changing area of law.

Legal Disclaimer: This article provides general legal information and is not legal advice. Laws vary by state and are subject to change. The information above reflects our best understanding as of March 2026. Consult a licensed attorney for advice specific to your situation.