In Maryland, turning 18 makes you a legal adult for almost every purpose the law recognizes, so what you can do at 18 in Maryland includes voting, signing contracts, consenting to your own medical care, marrying without permission, writing a will, enlisting in the military, buying a rifle or shotgun, playing the lottery, and being prosecuted as an adult if you break the law. A short list of activities still waits until 21: alcohol, recreational cannabis, tobacco and vaping products, handguns, and casino gambling.
The legal basis is straightforward. Under Maryland’s General Provisions code, an 18-year-old has the same legal capacity, rights, and responsibilities that someone 21 or older held before the law changed in 1973.1Maryland General Assembly. Maryland Code General Provisions 1-401 – Age of Majority
Voting, Jury Duty, and Selective Service
The Maryland Constitution guarantees every U.S. citizen who is at least 18 and a state resident the right to vote in all elections held in the state.2Maryland General Assembly. Maryland Constitution Article 1 – Section 1 You can register as early as 16, but you generally cannot cast a ballot until you turn 18. The one exception is a primary election that leads to a general or special election occurring after your 18th birthday.
Jury duty also becomes a possibility. To qualify you need to be a U.S. citizen, live in the county where you’re called, and be able to read, write, and speak English. A pending charge or past conviction for a crime punishable by more than one year of imprisonment disqualifies you, unless you’ve been pardoned.3Maryland General Assembly. Maryland Code Courts and Judicial Proceedings 8-103 – Qualifications for Jury Service
For men, turning 18 triggers a federal obligation that catches some people off guard: Selective Service registration. Federal law requires virtually all male U.S. citizens and male immigrants to register within 30 days of their 18th birthday.4Selective Service System. Selective Service System Failing to register can result in a fine of up to $10,000, up to five years of imprisonment, or both.5Office of the Law Revision Counsel. 50 USC 3811 – Offenses and Penalties Criminal prosecution is rare in practice, but the collateral consequences are real. You can lose eligibility for federal student aid, federally funded job training, federal employment, and, for immigrant men, U.S. citizenship. The registration window closes permanently at age 26.
Signing Contracts and Managing Money
Before 18, most contracts you sign are voidable, meaning you can walk away from them. After 18, you can enter legally binding agreements on your own: apartment leases, car loans, cell phone plans, credit card applications. No cosigner required. You can open bank accounts independently and take on debt in your own name. The flip side is full responsibility for those obligations, and creditors can pursue you if you default.
One wrinkle surprises many 18-year-olds heading to college. Turning 18 does not make you an “independent student” for federal financial aid purposes. The FAFSA generally considers you dependent on your parents until you turn 24, unless you meet specific criteria such as being married, a military veteran, a foster youth, or having legal dependents of your own. Most 18-year-olds still need to report their parents’ income on the FAFSA regardless of whether their parents actually help pay for school.
Maryland law also recognizes that some 18-year-olds are still in high school. If you’re 18 and still enrolled in secondary school, both of your parents remain legally obligated to support you until you graduate, turn 19, marry, or become emancipated, whichever comes first.1Maryland General Assembly. Maryland Code General Provisions 1-401 – Age of Majority
Making Your Own Medical Decisions
At 18, you gain full authority over your own medical care. You consent to your own treatment, control your medical records, and decide about procedures without anyone else’s input. Before 18, Maryland law only allowed minors to consent independently in limited situations, such as treatment related to substance abuse, sexually transmitted infections, pregnancy, contraception, or HIV prevention.6Maryland General Assembly. Maryland Code Health-General 20-102 – Capacity to Consent to Medical or Dental Treatment At 18, those special circumstances stop mattering. You have the same authority as any adult patient.
Body modifications also become straightforward. Maryland requires parental consent for body piercings on minors, and some counties have their own restrictions on tattooing anyone under 18. Once you’re an adult, those consent requirements no longer apply.
Marriage, Name Changes, and Wills
You can marry at 18 without any conditions. Maryland allows 17-year-olds to marry only with both parental consent and a court order.7Maryland General Assembly. Maryland Code Family Law 2-301 – Marriage Age At 18, you skip all of that.
Turning 18 also gives you standing in court as an individual. You can file a lawsuit or be named as a defendant in your own right, without a parent or guardian acting on your behalf. You can petition for a legal name change through the circuit court in your county without parental involvement.
Maryland law allows anyone who is at least 18 and legally competent to create a will.8Maryland General Assembly. Maryland Code Estates and Trusts 4-101 – Who May Make a Will Most 18-year-olds don’t think about estate planning, but if you own a car, have savings, or want to name a guardian for a child, a will is the only way to ensure your wishes are followed.
Military Enlistment
At 18, you can enlist in any branch of the armed forces without parental consent. Federal law allows enlistment as young as 17, but anyone under 18 needs written permission from a parent or guardian.9govinfo. 10 USC 505 – Regular Components: Qualifications, Term, Grade Once you turn 18, that requirement disappears.
Firearms at 18
Maryland allows 18-year-olds to purchase rifles and shotguns. State law prohibits selling a rifle or shotgun to anyone under 18, so your 18th birthday is the threshold. The specific model still matters, because Maryland bans certain firearms classified as assault weapons regardless of the buyer’s age.
Handguns are different. You must be at least 21 to obtain a Handgun Qualification License, which Maryland requires before you can buy, rent, or receive a handgun. The same age floor applies to handgun ammunition. A wear-and-carry permit also requires you to be 21, with a narrow exception for people who need one specifically for employment.
Lottery and Gambling
Maryland sets different age thresholds depending on the type of gambling. At 18, you can buy lottery tickets, play scratch-offs, participate in bingo, and bet on horse racing. Casino gambling is off-limits until 21, and that restriction covers slot machines, table games, and sportsbooks inside casinos. Online sports betting in Maryland also requires you to be 21.
Adult Criminal Responsibility
Turning 18 means full exposure to the adult criminal justice system. Any criminal charge you face at 18 or older is prosecuted in adult court, with adult sentencing ranges and a permanent criminal record. Maryland’s juvenile court handles cases for younger individuals, but that protection ends at 18.
What Still Waits Until 21
Several activities remain restricted until your 21st birthday, regardless of your legal adult status:
- Alcohol. Purchasing or consuming alcoholic beverages is illegal for anyone under 21 in Maryland.
- Recreational cannabis. Maryland legalized adult-use cannabis in 2023, but “adult-use” means 21 and older. Possession, purchase, and use of recreational cannabis by anyone under 21 is a civil offense punishable by a fine of up to $100. If you’re 18, you can register as a medical cannabis patient if you have a qualifying condition; the medical program operates separately from the recreational market.10Maryland Cannabis Administration. Adult-Use Cannabis FAQs
- Tobacco and vaping products. The minimum purchase age for tobacco products and electronic smoking devices is 21. Maryland previously carved out an exception for active-duty military personnel aged 18 to 20, but the legislature repealed that exception in 2024. No one under 21 can legally purchase these products in Maryland now.11Maryland General Assembly. Maryland Code Health-General 24-305 – Distribution of Electronic Cigarettes to Minors Prohibited12Maryland General Assembly. 2024 Regular Session – Senate Bill 220 Chapter
- Handgun purchases. You need to be 21 to obtain the Handgun Qualification License required to buy a handgun in Maryland.
- Casino gambling. All casino gaming, including in-casino sports betting and online sports betting, requires you to be 21.
The gap between 18 and 21 can feel inconsistent. You can sign a mortgage, enlist in the military, and face adult prison time, but you cannot buy a beer or place a bet at a blackjack table. Before you assume adult status covers a specific activity, check the age rule for that activity.