Background: Social Prescribing (SP) in healthcare relies on the implementation of new programs by a new type of workforce that interacts with both the health sector and the social care and community sectors. In an already complex and often fragmented health system introducing SP may create additional challenges for professionals implementing and delivering SP while seeking to “join-up” our fractured systems. Methods: An umbrella review was conducted (CRD42024572605) and five databases (MEDLINE, Embase, CINAHL, Scopus, PsycINFO) were searched to May 2024. Reviews were included if they discussed models of care where workers spanned multiple sectors, and coordinated services involving health, social or community care. A thematic data synthesis approach was used for analysis. Results: Twenty-six review articles were included, which synthesised 824 unique primary peer-reviewed sources. Barriers were reported more frequently than enablers. Barriers included unstable funding models; unclear role descriptions, role scope and role boundaries, leading to burnout; lack of shared infrastructure e.g. medical records platforms, guidelines and training courses; limited professional networks or communities of practice; unclear referral pathways and limited understanding of the link worker role among other professionals. Referral of highly complex cases to link workers who had limited training in trauma informed care or mental health skills to support clients. Enablers included clear role descriptions, tailored training and support networks, lived experience or deep understanding of the population being served and knowledge of local resources that could support clients; high level of health literacy across health problems and contexts, communication and rapport-building skills. Support for link-workers to maintain a tricky balance of developing trusting relationships with clients while maintaining professional role boundaries. Conclusions: To avoid link-worker burn-out, clarity of roles and role boundaries, cross-sector shared infrastructure, appropriate training, communities of practice and stable funding models must be considered at the outset when implementing social prescribing programs that span the health, social care and community sectors.