The gift from philanthropist David M. Rubenstein will maintain one of Washington's most popular attractions during difficult financial times, zoo officials said.
The pandas on loan from China previously had their stay extended through 2015 but the zoo had been having trouble securing corporate sponsorship for the program, The Washington Post reported.
The new funding will allow the zoo to concentrate on the sometimes frustrating effort to produce panda cubs, officials said.
This coming year is probably the last one the zoo will try to achieve a pregnancy with its current pair of giant pandas, they said.
In honor of the gift the zoo's Giant Panda habitat was being named the David M. Rubenstein Family Giant Panda Habitat, zoo officials said.