The Mid-America Business Conditions index hit 56.8 in April, compared with 58.2 in March.
The confidence index rose to 59.9 last month from 58.2 in March.
Creighton University economics professor Ernie Goss oversees the survey, and he says the supply managers surveyed "expect the upturn in housing to remain an important ingredient of the economic expansion."
The survey uses a collection of indexes ranging from zero to 100. Survey organizers say any score above 50 suggests growth while a score below 50 suggests decline for that factor.
The survey covers Arkansas, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma and South Dakota.