So my mom took my 11 year old brother to the dentist to get a crown done in March 2014.she paid the patient portion and everything else was supposed to be covered by the dental insurance. Since then all other dental visits were always paid by the insurance and patient portion was always paid. Everything was in good standing. But now, 2 years later, we receive a statement from the dental office saying that the insurance did not cover the crown that was done 2 years ago and that we owe 1,000 plus dollars for the crown from March 2014. Are we responsible for that? And if so, is there any way to appeal this?
Short answer - yes, you're responsible. Your mom, that is.
Longer answer: When you go to a doctor's office, you sign a statement that the insurance payments on the bill are estimates, and the actual amounts will be adjusted when the insurance pays. Whatever insurance doesn't pay - is on you.
You need to check with the insurance whether they in fact declined to pay, and if so - why. If they didn't decline, they should send you a statement saying how much they paid and how much you still owe, and if they did decline - they should send you an explanation for the reason. That explanation should also include the ways to appeal, although it is likely to be too late for that.