Community implementation of evidence-based practices (EBPs) for Attention Deficit/Hyperactivity Disorder (ADHD) is greatly lacking. A recent randomized community-based trial of an EBP for ADHD (Supporting Teens' Autonomy Daily; STAND) demonstrated suboptimal implementation and effectiveness outcomes. In the present study, we conducted an Innovation Tournament (IT) with agency staff stakeholders (N = 26) to identify barriers to successful implementation of STAND and implementation strategies for a revised service delivery model. We conducted member-checking of agency staff-generated ideas with parents (N = 226) and subsequent querying of additional parent (N = 226) and youth-generated (N = 205) strategies to improve care. Go-Zone plots were utilized to identify strategies with the highest feasibility and importance. Practical barriers (i.e., transportation, scheduling difficulties) and parent/youth engagement were the most commonly cited obstacles to successful implementation of STAND in community contexts. Eighteen "winning" implementation strategies were identified that survived member checking. These were classified as train and educate stakeholders (n = 5; e.g., train agency supervisors to deliver supervision, digitize treatment materials and trainings), engage consumers (n = 9; e.g., begin treatment with rapport building sessions, increase psychoeducation), provide interactive assistance (n = 2; e.g., add group supervision, increase roleplay in supervision), and use of evaluative/iterative strategies (n = 2; e.g., perform fidelity checks, supervisor review of session recordings). Parents and youth desired longer duration of treatment and increased focus on maintenance. Strategies will be developed and tested as part of a pilot effectiveness trial designed to refine STAND's service delivery model. [This is the online first version of an article published in "Administration and Policy in Mental Health and Mental Health Services Research."]