The Department of Energy plans to sell 14 million barrels of the nation's 40-year-old crude oil reserve this month as a way to bring in revenue to the Treasury.

Congress had required the oil reserve sale to fund programs under the terms of two bills it passed in previous years: A healthcare innovation bill it passed last year called the 21st Century Cures Act, and bipartisan budget legislation from 2015.

Under the Bipartisan Budget Act of 2015, the Energy Department is directed to sell a total of 58 million barrels of crude oil from the reserve fund, over eight consecutive years. The U.S. will sell 5 million barrels this fiscal year, which ends Sept. 30.

The Cures Act requires the Energy Department to sell 25 million barrels of crude oil over three consecutive years. The Energy Department will sell 9 million barrels this year.

The reserve, on the Gulf Coast, currently holds nearly 680 million barrels of oil. It was established 40 years ago in response to the Arab oil embargo.