Existing studies have well documented the economic consequences of population aging and its impact on inflation. However, the role of human capital in the nexus between aging and inflation is underexplored, particularly in Emerging Markets and Developing Economies (EMDEs). This study uses data from 123 countries, including 89 EMDEs, to investigate how human capital shapes the aging–inflation nexus. Alongside the use of the human capital index (HCI) from the Penn World Table, the study uses long-run historical education attainment data to construct a targeted measure of elderly human capital, i.e., years of schooling of the elderly. The finding reveals that aging is deflationary, and higher human capital and elderly human capital are significantly associated with weaker deflationary pressure. The study identifies critical thresholds. For instance, when HCI 3.3 for EMDEs, aging becomes inflationary rather than deflationary; similarly, for our targeted measure, the turning point occurs at 5.4 years of schooling among the elderly. By analyzing the channel, we find that the association is concentrated among the educated elderly labor force, consistent with educated elderly participating as active economic contributors rather than purely dependent consumers. Findings are robust to splitting the sample within EMDEs, alternative measures of aging, additional controls, and alternative estimation method, i.e., System Generalized Method of Moments (GMM). The study’s findings highlight important policy implications, including the need for lifelong learning policies to ensure macroeconomic resilience amid population aging.