Most US states set a minimum age of 21 to play at land-based or online casinos. If you are under the age of 21, it is impossible to register a new account with a reputable online casino. That’s because the most trusted operators conduct in-depth identity verification checks to ensure each new customer is legitimate. There are some US states where the minimum legal age for online gambling is 18 rather than 21. The states that legalized iGaming for those aged 18 and above include Georgia, Idaho, Hawaii, Kentucky, Montana, Rhode Island, Utah, Vermont, Washington DC, and Wyoming.