KT, one of Korea’s mobile network operators, terminated 2G service completely as of March 19, 2012. In this paper we explore diverse issues associated with this service termination, including conflicting interests observed in legal disputes. We then propose policy suggestions to facilitate mobile network operators’ smooth transition to advanced mobile communications services while protecting subscriber benefits. As other mobile network operators in Korea and worldwide are, or will soon be, facing similar issues, this study should serve as a useful reference for mobile network operators and telecommunication regulators.