Answer:
If the question refers to chemical analyses related to the existence of extraterrestrial
organic molecules, NASA's total budget for all activity in all aerospace projects in 2009
amounted to roughly 1/2 of 1 percent of the federal budget.
If the question refers to the search for extraterrestrial intelligence, then the answer is: Zero.
In the US, there has been no government funding for any SETI activity since 1995.