The Smithsonian Institution is offering buyouts to its federal employees for the second time in two years amid federal budget constraints.

Spokeswoman Linda St. Thomas said Tuesday that budget pressures led to the buyout offer. The museum complex will offer lump-sum payments capped at $25,000 to those who voluntarily resign or retire. They must decide by July 22.

Secretary G. Wayne Clough announced the buyouts and early retirement offer in a memo to staff. He wrote that it will help reshape the workforce to meet current and future programming needs under a new strategic plan.

In 2009, 144 federal employees took a buyout out of about 4,000 federal staffers.

The National Zoo has announced that seven employees will be laid off, saying federal funding hasn't kept up with the rising cost of animal care.