Objectives Mindfulness training (MT) guidelines recommend that trainers have familiarity and knowledge of the training group as well as extensive MT expertise. Herein, a "train-the-trainer" (TTT) dissemination model was investigated for military service members whose access to MT is threatened by a scarcity of qualified trainers. Methods US Army Master Resilience Trainer-Performance Experts (PEs), who had extensive familiarity with soldiers but no prior MT experience, participated in an MT practicum, and then delivered a 4-week MT program (Mindfulness-Based Attention Training, MBAT) contextualized for military personnel. Soldiers (n = 180) undergoing intensive military field training over the study interval were recruited as participants. MBAT was delivered to soldiers by PEs (n = 89) or by a trainer with extensive MT experience (Mindfulness Expert; ME, n = 45) but no military familiarity. The remaining participants served as no-training controls (NTC, n = 46). Soldiers' performance on sustained attention and working memory (WM) tasks was assessed before (week 0, T1) and after MBAT delivery (week 5, T2), and again 4 weeks later (week 10, T3). Results For all participants, sustained attention and WM performance declined over the high-demand field training interval (p < 0.001). Yet, the PE group declined significantly less in attentional (p = 0.040) and WM (p < 0.001) performance relative to the other groups. Conclusions These results suggest that TTT delivery of short-form MT by context-familiar trainers may be an expeditious route by which to increase access to MT in the service of promoting cognitive resilience in high-demand groups.