26 U.S. Code § 6322 - Period of lien
Unless another date is specifically fixed by law, the lien imposed by section 6321 shall arise at the time the assessment is made and shall continue until the liability for the amount so assessed (or a judgment against the taxpayer arising out of such liability) is satisfied or becomes unenforceable by reason of lapse of time.
1966—Pub. L. 89–719 inserted “(or a judgment against the taxpayer arising out of such liability)”.
Amendment by Pub. L. 89–719 applicable after Nov. 2, 1966, regardless of when title or lien of United States arose or when lien or interest of another person was acquired, with certain exceptions, see section 114(a)–(c) of Pub. L. 89–719, set out as a note under section 6323 of this title.