Things to Do When You Turn 18: The Checklist, Ranked by What Matters

What should you do when you turn 18? The checklist in one table

Fifteen moves, sorted by how strong the proof behind them is. All of the A’s cost nothing or close to it. Do those first and you have covered what matters most.

What do the A, B and C grades mean?

The grade says how sure you can be that a move works.

• A: a law, an official rule or strong research. You can count on it.
• B: official guidance from a government agency or professional body. Usually right.
• C: sensible, with thin proof. Use your own judgment.

Each move also gets a cost and a payback. A free move backed by federal law beats a costly one backed by a rule of thumb. Here is one written out in full:

The week you turn 18: what does the law now expect?

Most states set the age of majority at 18. Alabama and Nebraska use 19, and Mississippi uses 21. The drinking age stays 21 everywhere. From your state’s age of majority on, a signature on a contract counts. Before it, most contracts were voidable.

Voting

You can vote in federal elections if you’re a citizen, 18 by Election Day, and registered by your state’s deadline. Many states let you pre-register at 16 or 17. Start at vote.gov, which sends you to your state’s official site.

Selective Service

Almost all men ages 18 through 25 living in the US must register. Not registering is a federal felony, with a fine of up to $250,000 and up to five years in prison. A 2025 law requires automatic registration to start by December 2026. Until that system is clearly running, register yourself.

A health care proxy and a HIPAA authorization

At 18, your parents lose their usual right to see your records and decide for you. If you’re in an accident, nobody can speak for you unless you named them first. Your state’s health department, attorney general or state bar usually publishes the form. Most states require witnesses or a notary. In New York, any competent adult 18 or older can name an agent on a free state form with two adult witnesses.

REAL ID and jury duty

REAL ID enforcement started May 7, 2025. Ask for the star on your next license, or carry a passport to fly. Without either, TSA may allow a separate identity check that costs $45 for travelers 18 and older, but it isn’t guaranteed. A jury summons may also arrive by mail; answer it by the date printed.

Which money moves should an 18-year-old make first?

Two free choices at the bank do most of the work. Use an FDIC-insured bank or NCUA-insured credit union, which covers at least $250,000 per depositor. Then opt out of overdraft coverage on debit and ATM transactions, so a short balance means a declined card, not a fee.

Save your bank’s lost-card number in your phone. Report a missing debit card within two business days and your loss is capped at $50. Wait longer and it can reach $500. For a credit card, the most you owe for unauthorized charges is $50.

63% of adults said they would cover a $400 emergency with cash or its equivalent (Federal Reserve, Economic Well-Being of U.S. Households in 2025).

The CFPB suggests $500 as a first savings goal. That fund keeps you away from payday loans. A typical one costs about $15 per $100 for two weeks, close to 400 percent a year.

How do you start credit at 18 without getting burned?

Start by looking, not borrowing. Get free reports from Equifax, Experian and TransUnion at AnnualCreditReport.com. At 18 yours may be empty, which is normal. Checking it does not hurt your score.

Then freeze your credit at all three bureaus, free since September 2018. A thief can’t open credit in your name, and you can lift the freeze within an hour to apply.

When you do borrow, on-time payment matters most. FICO says payment history makes up 35% of its score, and a late payment stays on your report for seven years. Pay the full statement balance and you skip interest on new purchases. In August 2026, the average rate on card accounts charged interest was 22.36%.

Two rules surprise people. Under 21, a card issuer needs proof of your own income or a cosigner 21 or older. And a debit card never builds credit. The common “keep balances under 30%” advice is a rule of thumb with no official cutoff, so it grades C.

One request to refuse: cosigning for a friend. The FTC’s required notice says, “If the borrower doesn’t pay the debt, you will have to.”

What changes with your first paycheck and taxes?

Fill out Form W-4 on day one. The IRS Tax Withholding Estimator can fill it for you in about 25 minutes. Recheck it each January. Then read your first stub. In 2026, Social Security takes 6.2% and Medicare 1.45%, 7.65% together, often labeled FICA.

Many part-time workers don’t have to file a return but should. For 2025 returns, a single dependent generally had to file once earned income passed $15,750. If income tax was withheld below that line, filing is how you get it back. IRS Free File covered adjusted gross income of $95,000 or less in its October 2026 listing.

Side gigs follow a different rule. Net self-employment earnings of $400 or more mean you must file, and self-employment tax is 15.3%. No 1099 in the mail doesn’t mean no tax owed.

The federal minimum wage is $7.25, and a higher state or city rate applies where one exists. Overtime starts after 40 hours, counted one week at a time.

What should you check before you sign your first lease?

Read the whole lease before you sign, and get every spoken promise written into it. Renting rules are mostly state law. HUD keeps a tenant rights page for each state at hud.gov/states/[your state]/renting/tenantrights, with local housing and fair housing contacts.

Take dated photos and video of every room on move-in day and again on move-out day. Deposit rules vary. California gives the landlord 21 days to return a deposit with an itemized list, and deductions over $125 need receipts. Your state may differ.

The landlord’s insurance does not cover your things. Renters insurance does, along with liability and extra living costs if you have to move out for repairs. Housing discrimination is illegal under the Fair Housing Act; you have one year to file with HUD at 1-800-669-9777.

Never send a deposit for a place you haven’t seen in person. Pressure to decide fast and rent far below the area are the FTC’s warning signs.

Can you stay on a parent’s health insurance until 26?

Yes. You can join or stay on a parent’s plan until 26, even if you marry, move out or aren’t claimed as a dependent. On a Marketplace plan, coverage runs through December 31 of the year you turn 26. A job-based plan sets its own date. Take a photo of the insurance card now.

Losing that coverage opens a Special Enrollment Period. It covers losses in the past 60 days or expected in the next 60. Miss it and you may wait for Open Enrollment, November 1 to January 15 on HealthCare.gov.

Off a parent’s plan with low income? Medicaid takes applications all year. In expansion states, adults qualify below 138% of the federal poverty level, about $22,000 for one person in 2026. A work rule starts January 1, 2027, so check Medicaid.gov and your state.

Ask each doctor for your own patient-portal login, and save the No Surprises help line, 1-800-985-3059, for surprise out-of-network bills.

Which legal lines change the day you turn 18?

In most states, a criminal charge after your 18th birthday goes to adult court. The most common juvenile court cutoff is 17. Adult records follow you into job and apartment applications.

The line that surprises people most is about phones. Federal law makes any sexually explicit image of someone under 18 a crime to make, ask for, share or keep. Being the same age doesn’t matter, and the Justice Department calls the age of consent “irrelevant” here. AI-made images that look real are covered too.

The TAKE IT DOWN Act, signed May 19, 2025, made it a federal crime to post intimate images without consent, AI fakes included. Platforms must remove them within 48 hours of a valid request.

An online threat, even a joke, can bring up to five years in federal prison. Fake ID penalties are state law; in Minnesota, the buyer under 21 and the lender each lose their license for 90 days.

Which scams go after new 18-year-olds?

One rule catches most of them: only scammers demand gift cards, wire transfers or crypto. Government agencies will never message you on social media to ask for money.

• A job that asks you to pay for training or a starter kit, or to reship packages.
• A check that overpays you, with a request to send part back. A deposit showing in your balance doesn’t mean the check cleared.
• A text about a stuck package or a locked account. Forward it to 7726 and delete it.
• A call about a missed-jury fine or an IRS debt. Courts and the IRS write first.

If you already paid, call the bank or payment app the same day, then report at ReportFraud.ftc.gov.

What can wait until later?

Lower-proof and higher-cost moves can wait until your life asks for them:

• A Roth IRA. There’s no age limit, and the 2026 cap is $7,500 or your earnings from work, whichever is less.
• Debt and court rules. If a collector writes, you have 30 days to dispute in writing. LawHelp.org lists free legal aid by state.

How can a parent or grandparent help?

Skip the quiz. Sit together for one hour on the first-week items, since the medical forms usually name an adult. Then be the person they call about the first lease or the first odd pay stub.