Intergranular stress corrosion cracking (IGSCC) in above-ground carbon steel pipelines has been identified as a distinct mode of failure, different from the typical neutral pH and high pH SCC observed in buried pipelines. This form of SCC occurs under specific conditions, including operating temperatures ranging from 70°C to 190°C, exposure to wet mineral wool insulation, and insulation installations dating from post-2003. The affected carbon steel grades have included API 5L or CSA Z245.1 with specified minimum yield strength (SMYS) of 52 ksi or higher, as well as A106 Gr B, A234 WPB, and A516 Gr 70. Both field and laboratory tests have been conducted in the past to investigate this phenomenon. However, the underlying mechanism remains unclear. This paper presents a summary of the results obtained from various analytical methods, including chemical analyses, cyclic potentiodynamic polarization (CPP) testing, field crack inspections, U-bend autoclave tests, and a novel wet/dry cyclic test. It outlines the gaps in our understanding and highlights key findings that contribute to a better understanding of SCC in this specific context. Additionally, this paper discusses the development of test methods for screening susceptible materials, which is crucial for preventing failures related to intergranular SCC in above-ground carbon steel pipelines.