Neb. Rev. Stat. § 77-2037

Regardless of any defect in the proceedings in which such inheritance tax was determined, or the jurisdiction of the court to make such determination, the lien of the inheritance tax shall cease upon the first to occur of: (1) Ten years from the date of death of a decedent and no action shall be maintained for the determination, assessment or collection of such tax, unless a determination of the amount of such tax by the court having jurisdiction thereof shall have been made within such ten-year period, in which case such lien and the right to maintain any action for the assessment or collection of any tax shall cease five years after such determination or upon payment of such tax, whichever first occurs; (2) the payment of the amount of inheritance tax finally determined by the county court to be due with respect to property described in such proceedings; or (3) the release or discharge of any lien pursuant to section 77-2039 .