The nation's median income - the midpoint where half makes more and half less - didn't start rising again until 2014.
Middle-class household income has been rising steadily in recent years as the economy has rebounded from the deep recession and millions of Americans have found jobs again.
But by other measures, the US economy is still not working for everyone.
Middle class income smashed expectations and reached an "all-time high" across the United States in 2017, according to new statistics released by the United States Census Bureau.
The Census also reported that the US poverty rate declined modestly to 12.3 percent, the lowest level in years and a sign the economic devastation from the Great Recession is subsiding. The Census Bureau also said about 28.5 million residents did not have health insurance in 2017, not statistically different from the previous year.
The jump in income underscored in Wednesday's report, however, showcases the economy's recovery from the 2007-09 recession that was felt by many American households in 2017, largely driven by a robust labor market.
The unemployment rate has since declined to a near 18-year low of 3.9 percent and the economy continued to churn out jobs at a relatively brisk pace.