If Congress does not pass its budget by Oct. 1, all federal institutions will close to the public and all but essential personnel will be told not to report to work.
President Clinton has vowed to veto many of the spending bills making their way through Congress. It remains unclear whether Congress will actually finish their work before the fiscal year ends Sept. 30.
The museum, which receives about 60 percent of its $41 million budget from the federal government, would close to the public if the government shuts down. Only security guards would work during a closure.
The remainder of the museum's budget comes from private contributions.
"This seemed to be the prudent thing to do," said Mary Morrison, director of communications for the museum. "We would be required to close if there is no budget agreement."
According to officials at the museum, about 800 tickets have already been distributed for the first week of October.
The museum is already scheduled to be closed on Yom Kippur, Oct. 4. The only other day the museum closes is Christmas Day.
In the event of a shutdown, the museum plans to honor unused tickets any day at any time for 15 months. Ticket holders can also request a full refund of service charges from TicketMaster in writing.
Because of the high number of requests for tickets to the museum, visitors can obtain time- and date-specific admission tickets in advance through TicketMaster for a nominal service charge.
Any extra tickets are distributed daily by the museum on a first-come, first-served basis.