Background <p>International mobility has intensified routine contact between health systems and patients who do not speak the dominant language of care. In these encounters, language discordance is not a minor inconvenience but a mechanism through which existing social inequalities may be translated into delayed access, unsafe care, weaker informed consent, lower trust, and inefficient use of resources. Despite a substantial literature showing that professional interpreters improve communication and patient experience, interpreter provision remains uneven, especially in urgent care, off-hours care, and encounters involving less common languages.</p> Methods <p>This article presents an expanded narrative review of evidence published between 2000 and 2025 on language barriers, professional interpreting, migrant-sensitive care, and safety-related outcomes in health services. The synthesis was organised around political accountability, economic stewardship, and system-level implementation, with attention to rights, legal entitlements, avoidable waste, measurement, and governance. In addition to the literature review, the article uses conceptual cost reasoning based on publicly available tariffs from the region of Madrid (Comunidad Autónoma de Madrid) and develops illustrative vignettes to show how a hybrid model of on-demand remote and in-person interpreting may operate across primary care, emergency care, maternity care, and mental health.</p> Results <p>The reviewed literature indicates that language barriers are associated with more serious adverse events, interpretation errors, longer lengths of stay, weaker discharge communication, and underuse or patchy use of professional language support. Professional interpreters are associated with better comprehension, higher patient and provider satisfaction, better-quality discharge communication, and, in some settings, lower risk of communication-sensitive harm. The synthesis also suggests that the problem is not only linguistic. It is patterned by structural vulnerability, administrative precarity, unstable housing, work conditions, and variable institutional willingness to document and respond to language need. A hybrid service model, combining immediate telephone or video interpreting with reserved in-person support for high-risk and high-nuance encounters, is presented as a pragmatic and equity-oriented design for contemporary health systems.</p> Conclusions <p>Universal language access should be understood as core health-system infrastructure rather than as a discretionary support service. Reframing language access in this way can strengthen informed consent, patient safety, operational efficiency, and equity. The article proposes an integrated policy package covering statutory or stable funding, mandatory language documentation, electronic health record integration, workforce training and standards, and explicit governance for digital and artificial-intelligence-mediated tools. Together, these measures can help convert a widely recognised ethical imperative into routine organisational practice.</p>