The majority of land types in Indonesia consist of suboptimal lands. Their conditions are either too dry (i.e acidic dryland, arid land), or too wet (i.e swamps, peatland). This made the soil fertility low, highly acidic, and more costly to be managed. Despite the circumstances, suboptimal lands hold a significant contribution to support food security especially in the provinces where these land types share a large distribution. While the existing agricultural policies and practice tend to overlook the lands’ potential, this research attempted to offer a framework to mainstream the sustainable use of suboptimal lands and ways to embed them further into the nation’s development agenda. This paper adopted the Sustainable Land Management Mainstreaming Tool and used a qualitative descriptive approach to gather data and analysis based on literature study. It explored five key aspects that determine the viability of the mainstreaming effort: policies and regulations, incentives and financing mechanisms, land-use and territorial planning processes, and farmers development. Recommended policy options thus generated from each aspect and assessed using change space parameters that divided the result into high-priority, game-changing, and supplementary policies to mainstream the suboptimal land agriculture.