The impasse over the government shutdown and raising the country's borrowing limit showed no signs of breaking Tuesday.
House Republicans have insisted that any temporary funding bill contain concessions on President Barack Obama's health care law.
The Standard & Poor's 500 index closed down 20 points, or 1.2 percent, to close at 1,655.45. It was the 11th loss in the last 14 days, and the index's biggest drop in six weeks.
The Dow Jones industrial average was down 159 points, or 1.1 percent, to 14,776.53.
The Nasdaq composite fell 75 points, or 2 percent, to 3,694.83, also the largest drop in six weeks.