The global transition toward digital health ecosystems has accelerated the integration of financial technologies within healthcare delivery, yet rural populations remain at risk of digital exclusion. This systematic review examines the adoption of digital payment systems in rural healthcare, focusing on the interplay between technological drivers, multidimensional barriers, and the theoretical frameworks that govern user acceptance. Drawing on the Technology Acceptance Model (TAM), the Unified Theory of Acceptance and Use of Technology (UTAUT2), and the Diffusion of Innovation (DOI) theory, this paper analyzes how facilitating conditions, social influence, and personal innovativeness shape behavioral intentions. Results indicate that while digital payments significantly mitigate geographic barriers and enhance financial inclusion—particularly through specialized "health wallets"—adoption is frequently hindered by infrastructural deficits, low digital literacy, and deep-seated concerns regarding data security and trust. The review further incorporates specialized frameworks such as the COM-B model (Capability, Opportunity, and Motivation) and the Technology-Organization-Environment (TOE) framework to provide a deeper understanding of the environmental and organizational determinants of success. Case studies from Kenya’s M-TIBA ecosystem and India’s public-private partnerships demonstrate that successful implementation requires more than technical deployment; it necessitates an operational redesign that aligns with existing clinical workflows and local cultural values. Managerial implications emphasize the role of institutional leadership in fostering trust, the importance of "digital champions" in community training, and the need for policy frameworks that recognize connectivity as a social determinant of health. Furthermore, the review explores the nascent role of blockchain-based smart contracts and artificial intelligence in automating administrative functions and improving resource allocation in resource-constrained settings. The study concludes that achieving equitable access to digital healthcare financing requires a multi-pronged approach that addresses both technical "opportunity" and human "capability." These findings provide a strategic roadmap for healthcare administrators and policymakers aiming to bridge the urban-rural digital divide and ensure sustainable health system performance in a post-pandemic era.