I have not filed my taxes for a few years. Do I have to file?
Yes. But you should go to the most competent tax professional and file your returns voluntarily and pony up any money you believe you owe. This will help reduce the amount you have to pay as well as help ward off any forced collection or prosecution by the IRS. The IRS will eventually find you. You should still file your taxes when you believe you do not owe money to allow the statute of limitations to run and attempt to keep tax collectors at bay.