Russia’s invasion of Ukraine caused a major refugee crisis, particularly impacting Central and Eastern Europe. Ukraine has one of the highest prevalence rates of opioid use disorder (OUD) in Europe, which increases the risk of HIV spread due to injection drug use. Opioid agonist maintenance therapies (OAMT) are a gold standard treatment for OUD and the prevention of HIV spread. Refugees who were displaced and previously maintained on OAMT in Ukraine require reliable care continuity, but OAMT is often highly regulated making it difficult to access. Using an implementation science lens, we sought to understand the barriers and facilitators that might impede OAMT continuity. We performed 23 semi-structured interviews with displaced patients with OUD and providers of OAMT and harm reduction. Interview participants were purposively sampled to include individuals from the highest-impacted countries: Poland, Germany, Czechia, Slovakia, Romania, and Hungary. Interviews focused on existing provider networks and barriers that refugees on OAMT faced during displacement. Though networks existed, there was little collaboration between providers and key stakeholders, such as NGOs, in overcoming barriers. Moreover, existing formal networks were not leveraged for rapid problem-solving. We found that despite existing networks, providers encountered substantial barriers to successfully coordinating access and retention in OAMT for refugees. Owing to insufficiently leveraged coordination between providers, clinics frequently turned patients away due to insufficient capacity, language barriers, and financial coverage issues. The limited geographic distribution of clinics in larger countries, such as Poland and Germany, further inhibited refugees from accessing and remaining on treatment. To support countries and providers in responding to a rapidly evolving crisis, collaborative learning combined with rapid cycle change projects used by the Network for the Improvement of Addiction Treatment (NIATx) model could be deployed to promote collaboration between providers both nationally and throughout the European Union to guide continuity of OAMT.