The deal is that sports betting age requirements are set by each individual state, not the federal government. Most states went with 21+ when they legalized it, probably to match casino gambling ages. But Wyoming bucked the trend and went with 18+ for online sports betting when they legalized it in 2021. Same with Montana and a few others. The catch is that even in 18+ states, individual sportsbook operators like FanDuel or Caesars can still set their own higher age requirements, which is why you’ll see 21+ on most apps even in Wyoming. It’s confusing as hell because you’ve got state law saying one thing and the actual betting sites doing another. For what it’s worth, I think 18 makes more sense if you can vote and join the military, you should be able to bet $20 on a football game.