Are teeth aligners covered by insurance? In my experience the answer is no. Insurance companies have an interest in protecting themselves; especially when it comes to products that are capable of making their customers look "normal." They don't want any part of the process, and they don't want to be responsible for paying out of pocket for someone else's medical bills. So even though your teeth may look "normal", chances are they aren't.
One thing that insurance companies do allow you to purchase to help correct your teeth is a "bespoke" alignerco $300 off. These are the high-end aligners that come as part of a package. The reason you can usually only get them from your dentist is because it costs a lot more to make these things yourself. "bespoke" aligner costs several thousand dollars to make, so most dentists won't even consider doing it. The companies that sell the aligners, on the other hand, can afford to offer them at really competitive prices because they save on manufacturing costs as well as they only have to make a few to offer to dentists who have a list of approved patients.
So are teeth aligners covered by insurance? You'll have to ask that question again, because yes, they are. It may not be a great deal, but it sure beats having to pay thousands of dollars to your dentist for this treatment. There are quite a few "bespoke" aligner companies available online, but you'll want to check out some reviews of each company before making a purchase. There are quite a few that have been around for awhile, and who provide quality service.