In September of 2017, Hurricane Maria made landfall in Puerto Rico, bringing widespread damage to public systems across the island, which included particularly devastating impacts to local hospitals and medical facilities. Health care organisations operating on the ground played an essential role in hurricane response efforts as they attempted to address the medical needs of vulnerable populations. However, minimal research has discussed how the provision of post-disaster healthcare rested on the knowledge and participation of local communities. This study aims to fill these gaps by exploring the ways in which health care workers relied on their relationships with informal community networks to navigate the post-disaster landscape and provide adequate health services. This study uses post-disaster response data collected in Puerto Rico, which includes interviews with private, non-profit, and university-affiliated health organisations, as well as community health centers and emergent health outreach groups. Findings from this study highlight the critical role informal networks, community outreach, and relationship building play in response work as organisations attempt to overcome the specific complexities and challenges of operating in the post-disaster context. Furthermore, our research illustrates how deficient government support and systematic failings shift the burden of resilience building onto community members and organisations.