In California, the age of majority is 18. Family Code Section 6500 sets that line: anyone under 18 is a minor, and on your 18th birthday the state treats you as a legal adult.1California Legislative Information. California Family Code FAM – Section 6500 That single date rearranges your legal life, but it doesn’t hand you every adult privilege. Some rights arrive immediately, others still wait until 21, and a few federal obligations kick in whether you’re ready or not.
What Changes the Day You Turn 18
Before 18, your parents or guardians make most legally binding decisions for you. After 18, those decisions are yours, and so is the accountability that comes with them.
The clearest example is contracts. Under Family Code Section 6700, minors can enter into contracts but retain the power to void most of them. At 18, that safety net is gone. Leases, loans, and service agreements you sign are fully binding.
Other rights arrive on the same birthday:
- You can register and vote in every California election. Pre-registration filed at 16 or 17 activates automatically on your 18th birthday.2California Secretary of State. Who Can Vote in California
- You become eligible for jury duty if you’re a U.S. citizen, understand English well enough to follow a case, and live in the summoning county. Ignoring a summons can carry penalties.3Judicial Branch of California. Jury Service
- You can marry without parental consent or a court order.
- You can enlist in the military on your own signature. At 17, enlistment requires parental consent.
- You can sue and be sued in your own name, without a guardian ad litem.
Criminal responsibility also shifts. Before 18, charges are typically handled through the juvenile system, which emphasizes rehabilitation. At 18, every charge goes straight to adult court, with adult penalties on the table, including state prison.
Rights That Still Wait Until 21
Turning 18 doesn’t unlock everything. Several significant activities remain off-limits for three more years.
Alcohol and Tobacco
You must be 21 to buy, possess, or consume alcohol. Furnishing alcohol to anyone under 21 is a misdemeanor under Business and Professions Code Section 25658.4California Legislative Information. California Code BPC 25658 The same 21-year threshold applies to tobacco and vaping products under Business and Professions Code Section 22962.
Firearms From a Licensed Dealer
Under Penal Code Section 27510, licensed dealers generally cannot sell any firearm to anyone under 21.5California Legislative Information. California Code PEN 27510 Narrow exceptions apply: an 18-year-old with a valid hunting license can buy certain long guns that aren’t semiautomatic centerfire rifles, and there are separate carve-outs for active-duty military and honorably discharged veterans.
Credit Cards
The federal Credit CARD Act bars issuers from approving applicants under 21 unless the applicant shows an independent ability to make minimum payments or provides a cosigner.6Federal Deposit Insurance Corporation. ECOA – Understanding Age-Based Discrimination in Credit Card Lending You can legally sign the contract at 18, but most issuers will not extend unsecured credit without proof of income.
Privacy Over Medical and School Records
Two federal laws quietly redraw who controls your personal information at 18, and both catch families off guard.
Under the HIPAA Privacy Rule, parents generally act as their minor child’s personal representative and can access medical records. That access ends at 18. Providers cannot share your protected health information with your parents without your written authorization, even if a parent is still paying for your insurance.7HHS.gov. Personal Representatives and Minors
The Family Educational Rights and Privacy Act does the same for school records. Once you turn 18 or enroll in a postsecondary institution at any age, rights under FERPA transfer from your parents to you.8United States Department of Education, Student Privacy Policy Office. An Eligible Student Guide to the Family Educational Rights and Privacy Act (FERPA) A high school senior who turns 18 mid-year can block the release of grades and disciplinary records to their parents.
Financial Consequences of Turning 18
The age of majority sets off a chain of financial changes that reach further than the ability to sign a lease.
Child Support Usually Ends
Court-ordered child support in California generally terminates at 18. If the child is still attending high school full-time, support continues until graduation or age 19, whichever comes first. Parents can agree to extend support, and courts can order continued support for a disabled adult child who cannot be self-supporting.
Social Security Survivor Benefits End
Survivor benefits paid because a parent died stop at 18. They can continue to 19 if you’re enrolled full-time in elementary or secondary school, and they can continue at any age if you became disabled before 22.9Social Security Administration. Survivors Benefits
FAFSA Independence Is Not Tied to Age 18
This is a common misunderstanding. Turning 18 does not make you an independent student for federal financial aid. The FAFSA uses its own rules. For the 2026–27 school year, you’re independent only if you were born before January 1, 2003, are married, are a veteran, have dependents of your own, were in foster care or a ward of the court after age 13, or meet certain other specific conditions.10Federal Student Aid. Dependency Status Living apart from your parents or not being claimed on their taxes doesn’t qualify you. Most 18-year-old college freshmen still have to report parental financial information.
The Kiddie Tax Can Still Apply
The IRS “kiddie tax” rules can tax a child’s unearned income at the parent’s marginal rate. For 2026, the first $1,350 of unearned income is tax-free, the next $1,350 is taxed at the child’s rate, and anything above $2,700 is taxed at the parent’s rate.11Internal Revenue Service. Rev. Proc. 2025-32 The rules apply to children under 19, and to full-time students under 24 who don’t provide more than half their own support. Turning 18 alone doesn’t end them.
Selective Service Registration
Federal law requires most male U.S. citizens and male immigrants to register with the Selective Service System within 30 days of turning 18. Failing to register can block you from federal student aid, federal job training programs, and federal employment. The obligation runs until age 26.12Office of the Law Revision Counsel. 50 USC 3802 – Registration
Becoming an Adult Before 18
California recognizes two ways for a minor to gain adult legal status early: emancipation and marriage.
A minor between 14 and 17 can petition for emancipation. If granted, the minor can choose where to live, apply for a work permit, keep their own earnings, enroll in school, and obtain a credit card without parental permission.13Judicial Branch of California. Emancipation in California A judge has to find that the minor is already living apart from their parents with parental knowledge, has a lawful source of income, can manage their own finances, and that emancipation serves the minor’s best interests. Once emancipated, parents are no longer legally obligated to provide support.
Marriage also triggers emancipation. California has no statutory minimum age for marriage, but a minor must obtain both a court order and written consent from at least one parent or guardian.14California Courts. FL-910 Request of Minor to Marry or Establish a Domestic Partnership If a court permits the marriage and it is validly entered, California law treats the minor as emancipated.15California Courts. FL-915 Order and Notices to Minor on Request to Marry or Establish a Domestic Partnership Even with parental consent, the judge decides whether the marriage is in the minor’s best interest and can deny permission.