Mainstreaming climate change adaptation into plans and programs is one of the long-term strategies to address climate change, but as a relatively new approach, there is still little understanding of what it entails in practice. This paper contributes to the research field by presenting the challenges of mainstreaming climate change adaptation (CCA) as statistical indicators that characterise the adaptive capacity of systems in the province of Albay, Philippines. These challenges are classified into three categories - information, institutional, and resource - covering a range of 20 indicators generated through a survey that applied a purposive sampling technique in selecting respondents, and incorporated the scorecard approach to quantify the survey answers. Results suggest that the primary barrier of mainstreaming CCA into the local land use plans relate to institutional capacity, as represented by the institutional issues indicator. Data triangulation i.e., survey, depth interviews, consultations with key informants, and document reviews, identified these issues as: disharmonised or fragmented national laws and regulations; overlapping or multiplicity of policy requirements; and the lack of guidelines for mainstreaming CCA into the comprehensive land use plans. These issues are summarised as the lack of institutional mechanisms that support the mainstreaming efforts. Concerns relating to the information capacity, i.e., availability and access to information, are also highlighted as priority challenges to the mainstreaming endeavour. Meanwhile, the leadership component indicator, as signified by a climate change champion in Albay, is assessed as an opportunity for mainstreaming CCA.