The Institute for Supply Management’s nonmanufacturing index rose to 53.1 in March from 51.6 the prior month, the Tempe, Ariz.-based group said April 3.
The median projection in a Bloomberg News survey of economists called for a gain to 53.5. Readings greater than 50 signal expansion.
American shoppers began returning to stores and auto dealers as weather conditions improved and job gains helped brighten spirits.
Prior to the April 3 numbers, the index has averaged 53.7 since the recession ended in June 2009.
The pickup in optimism among service companies followed an earlier report showing a faster pace of expansion at manufacturers, indicating the economy was building momentum into the second quarter.