The Leading Economic Index rose for the fifth month out of the past six, having fallen flat in July. The last month in which the index ticked lower was in March of this year.
The index is a comparison to economic conditions in 2004, which have been assigned a value of 100.
"The September LEI suggests the economy was expanding modestly and possibly gaining momentum before the government shutdown," said Ken Goldstein, an economist at The Conference Board.
"Beyond the immediate fallout of the shutdown, the biggest challenge is whether relatively weak consumer demand, pinned down by weak wage growth and low levels of confidence, will recover during the final stretch of 2013 and into 2014," Goldstein said.