New York has now raised the minimum age to buy tobacco and electronic cigarettes to 21 years old, from 18.
The law, which Gov. Andrew Cuomo signed in July, went into effect Wednesday.
Cuomo says the goal is to prevent addictive cigarette and vaping products from getting to young people.
The New York Department of Health says nearly 40 percent of 12th grade students and 27 percent of high school students are now using e-cigarettes. They say the increase is largely driven by flavored e-liquids.
The Surgeon General says 88 percent of adult smokers started using tobacco as minors and 90 percent of those who purchase cigarettes for minors are between 18 and 20 years old.
Cuomo's administration has pushed to outlaw flavored e-cigarettes, but a court has blocked that ban for now.
The state is following New York City's lead. The city raised the minimum age to buy tobacco products to 21 five years ago.
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