Systems thinking approach to developing an integrated and patient-centred intervention model for multimorbidity care in primary care settings in India Multimorbidity is the existence of multiple long-term mental, physical, and cognitive disorders in one patient. These could include diabetes, hypertension, lung diseases, heart attacks, stroke, kidney failure, and liver problems or other conditions. Multimorbid conditions can share common disease causes and consequences. The rate of multimorbidity is rapidly increasing in low resource countries (low and middle-income countries - LMIC) such as India. Importantly, multimorbidity leads to reduction in quality of life, increase in use of health services and reduction in life expectancy. However, in management of multimorbidity, it is often considered as an assortment of disconnected diseases. Hence patients with multimorbidity receive less than optimal care.  A concerted effort from the health system for re-orienting the delivery of primary care is important in improving the quality of life of people with multiple chronic conditions. Our proposed study in primary care settings of Kerala, India will try to better understand the complexity of workforce strengths, system capabilities, human behaviours, link to social resources and their interactions most aptly framed from a health system perspective in developing an innovative and patient centred model for management of multimorbidity. We will adopt the following steps: 1. We will use different qualitative (discussions and observations) methods to investigate what is currently happening in our health facilities with services that multimorbidity patients receive. In this way we will understand the perceptions of health system managers, health care providers and patients in terms of the barriers and facilitators of provision of care for patients with multiple long-term (chronic) conditions.  2. We will identify successful models of interventions for managing multimorbidity in other settings by conducting a comprehensive review of available literature.  3. We will use this literature review and data from our research to develop context specific interventions for managing multimorbidity in primary care settings. Additionally, we will explore ways in which the care for people with multiple chronic conditions can be organised and integrated within the community through community health workers.  4. We will then use methods to visualise how different variables in a system are interrelated (causal loop model) and identify how changes in one variable affects others in the loop.  5. We will identify options for improving access to social resources (eg: accessibility for physical activity for females, rehabilitation services etc.,) for managing multimorbidity, which can then be incorporated into the intervention models developed in step 3 and 4.  6. Further, we will identify interventions that potentially have a more direct impact on patients, prioritise them and finalise them after incorporating comments from all stakeholders as in step 1.  7. Finally, materials and protocols will be developed for prioritised intervention items. Optimal involvement of clinical and health system leadership, engagement of all potential stakeholders including patients in the intervention development are unique to this project.  Finally, a detailed plan will be developed for formal evaluation of the developed intervention in a confirmatory study in future. The key lessons from this project may help to transform the current health-care delivery system into a patient-centered and coordinated system for managing multimorbidity in primary care. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.