Effective citizen engagement is crucial for the success of social health insurance, yet little is known about the mechanisms used to involve citizens in LMICs. This paper explores citizen engagement efforts by the National Health Insurance Fund (NHIF) and their impact on health insurance coverage within rural informal worker households in western Kenya. Our study employed a mixed-method design, including a cross-sectional household survey (n=1773), in-depth household interviews (n=36), 6 focus group discussions with community stakeholders, and key informant interviews (n=11) with policy makers. Findings reveal that NHIF is widely recognized, but knowledge of its services, feedback mechanisms, and accountability systems is limited. NHIF enrolment among respondents is low (11%). Majority (63%) are aware of NHIF, but only 32% know about the benefit package. There was higher awareness of the benefit package (60%) among those with NHIF compared to those without (28%). Satisfaction with the NHIF benefit package was expressed by only 48% of the insured. Nearly all respondents (93%) are unaware of mechanisms to provide feedback or raise complaints with NHIF. Of those who are aware, the majority (57%) mention visiting NHIF offices for assistance. Most respondents (97%) lack awareness of NHIF’s performance reporting mechanisms and express a desire to learn. Negative media reports about NHIF’s performance erode trust, contributing to low enrolment and member attrition. Our study underscores the urgency of prioritizing citizen engagement to address low enrolment and attrition rates. We recommend evaluating current citizen engagement procedures to enhance citizen accountability and incorporate their voices. Equally important is the need to build the capacity of health facility staff handling NHIF clients in providing information and addressing complaints. Transparency and information accessibility, including the sharing of performance reports, will foster trust in the insurer. Lastly, standardizing messaging and translations for diverse audiences, particularly rural informal workers, is crucial.