Coiled tubing (CT) bending fatigue has been the subject of much research. Slickline (SL) fatigue is the subject of more recent, ongoing research. Fatigue life tracking and prediction systems are available for both CT and SL. However, these systems do not adequately include the reduction in life due to corrosion. This paper discusses the CT and SL fatigue, and presents a new approach to handling the life reduction due to corrosion.