The Tower of LondonDX (2nd Edition TOLDX, Culbertson & Zillmer, 2005) provides a standardized measure of executive planning and problem solving. To enhance the measure's clinical and empirical utility, four contrasting Executive Planning Styles (EPS), were identified based on two different, but moderately related (i.e., rho = -0.37), TOLDX variables, Time to First Move and Total Move Score. The TOLDX normative data (Technical Manual) for participants ranging in age from 7 to 80years (n = 990) were utilized for study. The participants were drawn from sites in the United States and Canada. An individual's assignment to an EPS was based on initiation time and performance scores either one standard deviation above or below the mean for that individual's normative group. Using these criteria, four contrasting EPS were identified. The four Executive Efficiency constructs are labeled as: Q1 Efficient-Fast, exhibiting rapid, advanced planning skills; Q2 Efficient-Slow, suggesting careful, deliberate, and strategic planning; Q3 Inefficient-Fast, indicating pervasive impulsivity, nonstrategic planning, and an increased likelihood of poor rule-governed behavior; and Q4 Inefficient-Slow, suggesting limitations in executive planning, trial-and-error problem-solving, and possible cognitive limitations. The purpose of this analysis was to further differentiate the executive planning process of an established measure of executive function by combing two constructs (initiation time and performance) into four Executive Planning Styles. Executive planning is a dimension of complex human behavior, and the four-quadrant conceptualization of Executive Efficiency expands our understanding of this very important neuropsychological construct.