Abstract Objective Exploratory analyses on executive function performance between clinical groups was conducted using the Delis-Kaplan Executive Function System Advanced (D-KEFS Advanced) Trail Making Test (TMT). Our goal was to see if TMT could detect differences in the cognitive profiles of examinees diagnosed with attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and math learning disorder (MLD) clinical groups. Method Participants ages of 8 and 16, diagnosed with ADHD (N = 56), ASD (N = 27), or MLD (N = 25) completed the D-KEFS Advanced TMT. DSM5 diagnostic criteria were used for diagnosis. Additionally, participants with comorbid diagnoses across the three groups were excluded from the clinical samples. Mean Correct (with errors) Connection Time for the five conditions was captured for each clinical group, as well as error rates. Results Multiple differences were found, but only two reached significances at the p < 0.01 level. Unpaired t-test results revealed a statistically significant difference between ADHD (M = 9.34, SD = 3.16) and ASD (M = 7.00, SD = 3.16) groups in Mean Correct (with errors) Connection Time scores for TMT Number Sequencing, t(81) = 3.16, p = 0.002, 95% CI [0.87, 3.81]. Additionally, Mean Correct (with errors) Connection Time scores for TMT Switching-Distraction condition between ADHD (M = 8.41, SD = 2.51) and ASD (M = 6.48, SD = 3.04) groups was statistically significant, t(81) = 3.06, p = 0.003, 95% CI [0.67–3.19]. Conclusion Overall, these preliminary findings suggest good clinical utility; however, further research is needed to determine if performance differences can aid in the evaluation of patterns of cognitive difficulties between groups.