Where can I watch Contagion in United States?

In the 21st Century, terrorists have developed a new way to strike: disease. Not only have they created a deadly Level Four Ebola virus, their first victim is the President of the United States. The virus is particularly contagious and is spreading. If a cure cannot be found, the only chance for saving the world from epidemic is for the army to destroy the hospital and the town where the victims, including the President, are currently contained. The clock is ticking. As doctors search for a cure the military seeks to annihilate them all in a race to stop the deadly path of the contagion. Can the spread be stopped before its too late?