While A Raisin in the Sun certainly bears elements of a tragedy, including a bleak inciting incident, plainly flawed characters, and an incredibly cynical view on the true nature of humanity, particularly where greed is concerned, the play falls a bit more neatly into the category of a drama. The main distinction that sets it apart from a traditional tragedy is that it lacks a tragic hero, or a particular character that suffers a grim fate due to an insurmountable flaw.
Indeed, the action of the play revolves around an entire family, exploring the relationships and dynamics between the characters through conflicts that tend to be more episodic. This are all elements of a drama. Furthermore, though there are many tragic turning points and dark eventualities in the play, it does end on a positive note.