The possibility that the United States could default on its obligations has created considerable uncertainty for treasurers responsible for short-term corporate investments. And analysts point out that Treasuries and other government securities constitute a huge portion of the investment-grade paper that's available, leaving investors limited options should they choose to exit the Treasury market.

Lance Pan, director of investment research and strategy at Capital Advisors Group, says that while he views the risk of a U.S. default as "extremely low," treasurers should be prepared for a stalemate in Washington that could last for weeks, and for the stresses that might place on their company's liquidity.

"If you have anything coming due between now and the middle of August, try to have some money set aside other than from Treasury bills," Pan says. "If we were to have a temporary default, which we don't think will happen, at least you can wait it out. You don't want to get trapped in the three or four days when you need that money.