<p>Despite the prominence of sustainment as a construct in implementation science frameworks, there is limited literature on factors influencing the continued delivery and reach of evidence-based interventions in carceral settings after initial funding periods end. Extending previously published research on initial establishment of these programs with federally funded implementation support, this study reports on the post-intervention impact of jail-based programming to link people with opioid use disorder to medication treatment upon community reentry to assess whether and how linkage programming was maintained. In the five jails that sustained linkage program staff, only 4.9% of participants enrolled during the sustainment phase were successfully linked to community-based treatment, compared with 11.8% during the intervention phase. Interviews with linkage staff supervisors revealed that several factors salient to initial program implementation – adopter training and support, services and access, and systems and training – exerted ongoing effects during the sustainment period, demonstrating that preliminary implementation conditions may shape long-term reach. During the program sustainment period, these issues included restrictions on program eligibility criteria to reduce jail healthcare costs and deterioration of related clinical offerings (i.e., provision of in-house medication treatment). Additionally, challenges with maintaining data collection consistency after termination of the study’s data management infrastructure and reporting requirements resulted in significant missing data. Findings emphasize the need for enduring technical assistance and data-tracking infrastructure to support and monitor the impact of jail-based linkage programs as a component of the overall opioid use disorder continuum of care.</p>