Background As direct-acting antivirals (DAAs) have been scaled up, HCV reinfection has also risen. There are extensive quantitative studies focusing on HCV reinfection in the DAA era, however qualitative studies are lacking. A scoping review was conducted which found seven studies relating to people with lived/living experience of reinfection. A second scoping search determined there were no studies relating to healthcare professionals’ opinions of reinfection in the DAA era. The two research questions were: 1) What is the lived experience of PWID who have experienced reinfection in the DAA era and 2) How can healthcare professionals help us to understand opportunities and challenges in service provision and care, and how this may impact upon HCV reinfection amongst PWID? Methods Purposive sampling was used for both studies. Interviews were carried out remotely via phone call/video call. For people with lived/living experience of reinfection (PLEoR), participants were included if they had experienced a reinfection in the DAA era. Their interviews were analysed using interpretative phenomenological analysis. The HCP participants included HCPs who were working to test, treat or diagnose HCV. The analysis method for HCPs was thematic analysis. In order to bring the results of these two studies together, the socio-ecological model was used. This gave an overview of the micro-, meso- and macro-social influences of reinfection. Findings PLEoR: Nine PLEoR were interviewed. The group experiential themes (GETs) were split into three sections: before reinfection, after reinfection and avoiding reinfection. PLEoRs GETs explored aspects such as environment, stigma and relationships. HCPs: Thirteen HCPs were interviewed. A total of five themes were formed: acknowledging the social context of reinfection, exerting power & control, seeking accountability, inflexibilities & limitations within services, and strong partnerships and relationships. Discussion This PhD provides a timely insight into HCV reinfection from the perspective of both HCPs and PLEoR. More work is needed to address the stigma of HCV reinfection and how this manifests for PLEoR. The treatment approach for reinfection has to include a more holistic approach, looking at the entire individual rather than just their reinfection. Better resources and stronger partnerships are also needed to enable HCPs to provide support for PLEoR and those at risk of reinfection.