Problems in the transmission sector have been attracting attention from Congress and the general public. Among the issues raised thus far are as follows: severe technical constraints in transmission, insufficient transmission capacity especially during peak periods, insufficient contracting by NGCP for ancillary services, delays in transmission projects, absence of transmission connection in some renewable energy zones, and weaknesses in regulation. Knowledge gaps on the root causes of these problems exist. This study will thus contribute to closing the gaps and identify what policies can be recommended to reform the transmission sector in the country. The study generally aims to uncover issues in the Philippine power transmission sector, why these issues arise, and how to resolve these issues.