The Iowa 150 designation has been a part of the primary highway system since its inception in 1920. The current route was formed in 1941. The route extended from Calmar to Davenport, by way of Cedar Rapids. In 1969, the route was truncated at Cedar Rapids, with part of the old route becoming Iowa 130. In 1984, it took its current form when the southern part of the route was shifted over the former Iowa 101. Most of the abandoned part of Iowa 150 became Iowa 920 until July 1, 2003.