This study examines curriculum vitae (CV) data from 447 scientists and engineers at academic research centers in the United States, ranging from post-doctoral researchers to full professors and research directors in order to figure out the pattern of scientific discipline trajectory and the relation of the scientists discipline mobility to productivity. This study shows that natural sciences have highest percentage of scientists who have the same bachelors degree field as their highest degree field and higher degree of mobility across the disciplines is negatively associated with their productivity. On the contrary, for life sciences, higher degree of mobility across the disciplines is positively associated with scientific productivity.