Conventional definitions of gifted underachievement have drawn a practical and structural divide between gifted underachievers and twice-exceptional students. Eligibility criteria, research practices, and intervention models have tended to treat these groups as mutually exclusive, even though their profiles and needs frequently overlap. This chapter examines this divide and explores how narrow definitions, static ability–achievement comparisons, and fragmented supports exclude underachieving, twice-exceptional students and limit their access to underachievement interventions. Given this complexity, labeling gifted underachievement should be more inclusive. When used constructively, labeling can itself serve as an intervention by signaling potential and opening access to supports. Without such inclusive framing, underachieving, twice-exceptional students remain siloed from gifted underachievers, and supports stay fragmented. This chapter explores implications for identification practices and intervention design, emphasizing dual-focus approaches that integrate academic skill development with psychosocial supports to better nurture the potential of all underachieving gifted learners, including those who are twice-exceptional.