BACKGROUND: In order to accelerate universal health coverage, Nigeria’s National Health Insurance Scheme (NHIS) decentralized the implementation of government health insurance to the States in 2014. Lagos has passed its State Health Scheme (LSHS) into law with a statewide roll out set to commence in 2018. The LSHS aims to improve access to quality care by reducing the financial burden of obtaining care for Lagos residents. Public and private healthcare providers are a critical component of this ambitious insurance roll out. Yet, little or no understanding exists on how to engage providers, the factors that influence their participation in insurance and expectations from the LSHS. In addition, little is known about the geographic distribution of NHIS accredited facilities and enrollees in Lagos State. METHODS: This study used a mixed-methods cross sectional design to analyze primary and secondary data. Primary data included both quantitative and qualitative data and were collected from representatively selected 60 healthcare providers in 6 Local Government Areas (LGAs) in Lagos State through questionnaires probing issues on the challenges and benefits of insurance participation, capacity pressure, resource availability and changes in financial management. Secondary data were obtained from NHIS and Lagos State inventory of health facilities, and household survey reports, and were visually mapped using a geographic information system (GIS) software. RESULTS: Facilities participating in insurance were more likely to be bigger with mid to very high patient volume and workforce. In addition, private were more likely than public facilities to participate in insurance. Furthermore, increase in patient volume and revenue were motivating factors for providers to participate in insurance, while low tariffs, delay and denial of payments, and patients’ unrealistic expectations were inhibiting factors. Also, NHIS enrollees were more likely to be located in the urban than rural LGAs. However, many urban LGAs have larger population sizes and as a result, were also characterized with higher number of non-NHIS enrollees and fewer NHIS accredited facilities. For the LSHS, many private facilities anticipate an increased patient volume and revenue but also worry that low tariffs without guaranteeing a high patient volume would be a major challenge. For many public facilities, inadequate infrastructure, lack of workforce, and insufficient drugs and commodities remain major challenges. CONCLUSION: For the LSHS to be successful, effective contracting of healthcare providers especially those in the low income and densely populated LGAs is essential. However, this would require that provider payment is adequate and regular. In addition, the government would need to invest heavily in improving the infrastructure and the amount of workforce, drugs and commodities available to public facilities.