A federal tax lien is a legal instrument that secures the claim of the United States in the right, title, and interest of a debtor taxpayer's assets. In most states, you can buy a home with a federal tax lien on it. You are not provided access into the house prior to the auction. You will have the address in advance and you should at least drive by. When faced with a mountain of unpaid tax debt, your best bet is to work with the IRS in order to prevent the execution of a federal tax lien. If you do have a Federal Tax Lien filed against you then your options for financing anything are nearly impossible.