Healthcare equity largely depends on primary healthcare (PHC) because it is needed in underdeveloped areas where people still cannot get healthcare widely. CHNs have played a critical role in increasing PHC coverage especially in the service provision, promotion/improvement of health and support of maternal child care. But they have a lot of untapped potential because of a lack of policies, skilled manpower, and a systemic solution. This review discusses the effects and functions of CHN-led interventions in underserved environments. To find these studies, the literature search was carried out in three databases such as PubMed, Scopus, and Google Scholar of the most recent articles during the period between 2015 and 2025. It concentrated on those interventions that included CHNs throughout education, preventive care, and maternal services. Results indicate the CHNs play major roles in task-shifting, immunization campaigns, antenatal care, and disease prevention. They make services more accessible in regions with shortage of physicians. There are, however, some problems that do not allow full integration into PHC systems, including poor training, incentives, and shortage of workforce in rural areas. In its research conclusions, the study suggests policy change and strategic investment towards upscaling the functions of CHNs on Universal Health Coverage (UHC).