A stay order entered by a district court is appealable as a final judgment under 28 USC 1291 if it effectively places the plaintiff out of court.  An indefinite stay to be ended only upon the occurrence of an external event that is not time delimited.  If the stay lasts 18 months or longer, the stay is not automatically appealable, but it is a “guidepost” for determining that the stay has effectively put the plaintiff out of court.