Federal Taxes owed

Oregon; My husband and I owe the IRS a lot of money from our 1993 tax return. They haven't been bothering us about it, but I'm afraid they will start again soon. Is there a statute of limitations on federal taxes? If so what is it or where can I find more info or help in this matter? Thanks!

In the case of taxes assessed after November 5, 1990, if the IRS has assessed the tax within the statutory period of limitation (usually 3 years after the return is filed), the tax may be collected by levy or a proceeding in court commenced within 10 years after the assessment or within any period for collection agreed upon in writing between the IRS and the taxpayer before the expiration of the 10-year period.