Abstract Background Despite South Korea’s achievement of Universal Health Coverage (UHC), regional health inequities persist as a significant public health challenge. Traditional urban-rural classifications often fail to capture the nuanced spatial dynamics of modern settlement patterns. This study aimed to evaluate the prevalence of hypertension (HTN) and diabetes mellitus (DM) across the urbanization gradient—Cities, Urbanized, and Rural areas—using the UN-recommended Degree of Urbanization (D