Economists forecast that the index was unchanged in September at 60, according to Bloomberg.
The index, which measures how builders rate present and future market conditions for new home sales, improved in August. Builders remained confident that low mortgage rates and a healthy labor market would drive sales, especially after the strong jobs report in July.
Some markets reported softer sales because of regulatory bottlenecks, scarce land lots, and labor shortages.
The index has been relatively flat over the past year, excluding a brief spike last fall when activity rose ahead of the introduction of tighter rules on loan disclosure.