Analysis of nearly 420,000 participants across three major cohorts reveals that individuals with lower socioeconomic status face 33% higher risks of developing cardiometabolic diseases and progressing to multimorbidity. The strongest disparities emerged in diabetes onset (45% higher risk) and stroke-to-multimorbidity transitions (51% higher risk). Lower-SES individuals developed their first cardiometabolic condition nearly half a year earlier and progressed to multiple conditions 0.76 years sooner than higher-SES counterparts. This socioeconomic health gradient represents one of the most comprehensive demonstrations yet of how financial disadvantage literally accelerates biological aging. The findings illuminate why poverty remains such a potent predictor of premature mortality—it's not just about healthcare access, but about the cumulative physiological toll of economic stress across decades. The research spans diverse populations from the UK, Europe, and South Korea, suggesting this pattern transcends cultural boundaries. However, as a preprint awaiting peer review, these striking disparities require validation. If confirmed, the results argue for treating socioeconomic intervention as preventive medicine, potentially offering more population health benefit than many clinical treatments targeting individual risk factors.