One-year program guarantees funds in participating money market accounts to encourage market stability.  Treasury provides up to $50 billion in financing from the Exchange Stabilization Fund. The Treasury will charge mutual funds a small insurance coverage fee. As of March 31, 2009, all of the major mutual fund companies had joined the program.

The Guarantee Program was put in place after one of the country's largest funds, the Reserve Fund, suffered a run on assets after the Lehman Brothers collapse. The Treasury voiced concerns over mutual funds shares falling below $1 per share, or "breaking the buck." At the time of the program's creation in Sept. 2008, mutual funds accounted for over $3.4 trillion in investor funds.

On 3/31/2009, the Treasury announced this program's extension through September 18, 2009.

On 9/18/2009, the Treasury released a statement announcing that the program is over, providing over $1.2 billion in revenue from coverage fees for the Treasury.