BackgroundMigrant populations are less likely to use health services or obtain prescription drug coverage in Canada, compared to their non-migrant counterparts. This research examines factors that influence migrants' access to prescription drugs. It explores factors that impede migrants’ access to essential medications and the mechanisms in place to assist uninsured and under-insured immigrants and refugees. This study aims to inform key policies and practices pertaining to healthcare and prescription drug programs for immigrants and refugees. MethodsA constructivist grounded theory methodology was employed to facilitate the development of an integrated set of theoretical concepts that synthesize, interpret and display processual relationships related to prescription drug coverage access for immigrants and refugees. Following ethics approval, 25 migrant patients and migrant-serving providers were interviewed using semi-structured interviews between July and December 2019 in Ontario, Canada. Qualitative data collected from key informant interviews were analyzed using grounded theory techniques and a constant comparative approach. ResultsParticipant perspectives on migrants’ experiences accessing prescription drugs revealed four challenges: informational gaps, financial constraints, coverage inconsistencies and social differences. These impediments to medication access led to refusals of care, medication anxiety, coverage unawareness, coping behaviours to manage the loss of access to prescription drugs and long-term health consequences. Supports identified include navigational aid, providers who are coverage knowledgeable and culturally sensitive, and short-term solutions such as funds, samples and compassionate programs. Gaps in short-term supports were perceived by participants, who proposed key policy and practice recommendations, primarily in support of universal pharmacare. ConclusionAddressing barriers to medication access for migrant populations involves intersectoral policy approaches, such as universal pharmacare complimented by drug monitoring system safeguards and informational supports. These strategies aim to alleviate difficulties migrant patients experience upon accessing medications they need.