My dentist told me that I need Invisalign but that my insurance doesn't cover it, what should I do?

Not a lot you can do exept change insurance companies or have your current one add on ortho coverage and then they will only cover a portion.

But they have to be sure to use the right insurance codes.  They insurance company does not care if braces are glued to the teeth or if you use removable aligners.  As long as the goal is to move teeth, it should be covered.

Invisalign is coded as comprehensive orthodontics.  If insurance pays for braces, they don't ask what tool was used.  If the dentist is using the wrong code, they might be denied.  If they are coding it "limited orthodontics" or "removable appliance therapy" there may not be a benefit.

Even if insurance is paying something, it is usually not 100%.  It would be important to know the total fee for treatment, what the insurance will pay (max out at $1000?) and the difference.  You may find that insurance isn't going to pay much at all no matter what you are doing.

Just because insurance won't pay for something doesn't mean it shouldn't be done.  It just means they wont' pay.