An integrated circuit device includes a first transistor comprising a first conductivity type, which includes a first channel region and a first source/drain region, a second transistor comprising a second conductivity type, which includes a second channel region and a second source/drain region, a first contact structure that contacts the first source/drain region and comprising a first length, and the first contact structure extends from above the first source/drain region and beyond an uppermost surface of the first channel region by a first vertical distance, and a second contact structure that contacts the second source/drain region and having a second length that is greater than the first length, the second contact extends from above the second source/drain region and beyond an uppermost surface of the second channel region by a second vertical distance, which is greater than the first vertical distance.