Contemporary means literally belonging to the present time, so an artist who has created Art in a style easily recognizable as modern , even if he is dead can be defined as a contemporary artist.
Contemporary art is art produced at the present period in time. Some define contemporary art as art produced within "our lifetime," recognizing that lifetimes and life spans vary. However, there is a recognition that this generic definition is subject to specialized limitations.
Contemporary art includes, and develops from, Postmodern art, which is itself a successor to Modern art. In vernacular English, "modern" and "contemporary" are synonyms, resulting in some conflation of the terms "modern art" and "contemporary art" by non-specialists.
The non-official definition says that "contemporary artist" are those whose peak of activity can be situated somewhere between the 1970s (the advent of postmodernism) and the present day.
Artists must meet some criteria: http://en.wikipedia.org/wiki/List_of_contemporary_artists
Salvador Dali is not considereded as contemporary, but not because he is dead: he doesn´t meet the criteria. Francis Bacon (+1992) is considered a contemporary artist, as well as Lucien Freud (+2011).