Neb. Rev. Stat. § 25-1902: Neb. Rev. Stat. § 25-1902

(1) The following are final orders which may be vacated, modified, or reversed:

(a) An order affecting a substantial right in an action, when such order in effect determines the action and prevents a judgment;

(b) An order affecting a substantial right made during a special proceeding;

(c) An order affecting a substantial right made on summary application in an action after a judgment is entered; and

(d) An order denying a motion for summary judgment when such motion is based on the assertion of sovereign immunity or the immunity of a government official.

(2) An order under subdivision (1)(d) of this section may be appealed pursuant to section 25-1912 within thirty days after the entry of such order or within thirty days after the entry of judgment.