Aims: Social health insurance and other forms of prepayment health schemes are effective approaches to enhancing access to available healthcare services. While prepayment schemes are generally common and well established in developed countries, they are relatively new and in the early stages of development in sub-Saharan countries, including Nigeria. Social health insurance in Nigeria, hitherto centralized, has devolved to the subnational state levels. The Oyo State Health Insurance Scheme, which is managed by the Oyo State Health Insurance Agency (OYSHIA), is one of the subnational schemes. The present study is a follow-up on the first three-year performance assessment of OYSHIA. The aim is also to assess the performance of the scheme and, most importantly, whether the recommendations made in the first study were used and if these recommendations have had a desirable impact on the scheme. Methods: Secondary data on enrolment in the social health insurance scheme of Oyo State between July 2020 and June 2023 were downloaded from the server of OYSHIA. The data were collated and analyzed. Data extraction, cleaning, and analysis covered a period of one and a half months (February–AApril, 2024). Excel software was used to analyze the data. Descriptive statistics were used to summarize the data. Population coverage distributions were expressed as frequencies and percentages. Frequency tables and graphs were generated to disaggregate the findings. Results: Although population coverage was still generally low, as it was in the first three-year performance assessment of the scheme, However, the present study shows that population coverage in the informal sector is very encouraging. Conclusions: In the absence of external limitations, the Oyo State social health insurance scheme has the potential to perform and achieve universal health coverage. Acknowledgements: The authors wish to acknowledge the Oyo State Health Insurance Agency for their permission to make use of the data and to submit the manuscript for publication. All enrollees are also appreciated. Contributions: David Adewole conceived and designed the study. Sola Akande, Boluwatito Orimadegun, and Ganiyu Owolabi were responsible for the data collection and analysis. Adewole, Akande, Orimadegun, Osungbade, and Owolabi contributed equally to the manuscript write-up. All authors read through the manuscript draft a second time. All authors agreed to the final manuscript.