Background <p>Data on factors that influence patient and caregiver preference for long-acting injectable (LAI) formulations of antipsychotics are limited in bipolar I disorder (BP-I), particularly regarding longer dosing intervals. The objective of this study was to explore healthcare experiences, preferences for LAI dosing frequency, and factors influencing preferences for a hypothetical LAI administered once every 2 months, in people living with BP-I, caregivers, and prescribers.</p> Methods <p>This qualitative interview study recruited people living with BP-I currently treated with a once-monthly LAI, caregivers, and prescribers from the USA and Canada. In semi-structured interviews, participants were asked about their treatment experiences, views on an ideal treatment, and preferences on LAI dosing frequency. Interview transcripts were analyzed descriptively for key themes.</p> Results <p>Twelve people living with BP-I currently treated with a once-monthly LAI, five caregivers, and five prescribers were interviewed. All three participant groups perceived frequency of administration and remaining on the same antipsychotic as key features of an LAI; prescribers also considered previous responses to treatment, treatment access, and the need to maintain control of medication important when prescribing. Participants were positive about an LAI administered once every 2 months compared with LAIs in general due to improved convenience, reduced patient and caregiver impact, and the potential to feel well and stable for longer.</p> Conclusions <p>Participants were positive about a potential transition to an LAI given once every 2 months. As each participant group has unique preferences for LAIs and treatment goals, these should be discussed during healthcare interactions to ensure that targeted disease management goals are met.</p>