As people living with HIV are living longer lives, they have a correspondingly greater opportunity to enjoy long-term romantic and sexual partnerships, including with persons who do not live with HIV ("serodiscordant" relationships). In these dyads, asymmetries may emerge in access to social resources between partners. In this paper we examined how serodiscordant couples access informal (interpersonal, such as family and friends) and formal (practitioner, such as doctor or social worker) social resources for health. We recruited 540 participants in current serodiscordant relationships, working with 150 AIDS service organizations and HIV clinics across Canada from 2016 to 2018. Our findings demonstrate that partners with HIV have greater access to formal resources than their partners (through health care professionals, therapists/counselors/support workers), while both persons have similar access to resources through informal social relationships (family and friends). Furthermore, the findings indicated that HIV positive partners accessed more varied forms of support through formal ties, compared to HIV negative persons. We offer recommendations for changes to how HIV-negative partners in a serodiscordant relationship are served and cared for, and particularly, the importance of moving toward dyad-focused policies and practices.