Aiming to explain the structural nexus between the fossil fuel-based development model, public health erosion, and the commodification of healthcare in Iran from 1989 to 2021, this study introduces the concept of "carbon-based biopolitics" as an innovative analytical framework. Adopting a qualitative-historical approach, this research utilized a mixed-methods design comprising a documentary analysis of 659 cabinet resolutions and high-level policy documents, thematic analysis of 11 in-depth interviews with experts based on Braun and Clarke’s six-phase model, and quantitative modeling using the Generalized Method of Moments (GMM) with time-series data extracted from the Central Bank, the Statistical Center of Iran, and the Ministry of Health. The research findings and GMM model results reveal that despite the discursive differences among various administrations, a form of "institutional continuity" and "structural identity" persisted in policymaking, where administrative transitions had no significant impact on sustainably reducing the share of out-of-pocket (OOP) payments. Causal process tracing demonstrates that the continuation of the fossil economy intensified environmental pollution, leading to the "structural production of illness". In response, rather than addressing root causes through prevention, the healthcare system adopted "incomplete privatization" and treatment-centered policies, thereby shifting the financial burden of biological erosion onto households—a trajectory highlighting a persistent gap between the "discursive justice" of high-level documents and "institutionalized justice" in implementation. Ultimately, carbon-based biopolitics reveals that pollution, the production of illness, and the healthcare market constitute a self-reproducing cycle, indicating that achieving health equity requires moving beyond sectoral reforms toward a low-carbon development model, enforcing the "polluter pays" principle, strengthening independent state regulation, and establishing sustainable, institutionalized financial protection.