BACKGROUND: Staging criteria for heart failure (HF) range from stage 0 (without risk) to being at risk (stage A) to presence of cardiac structural/functional abnormalities (stage B) to symptomatic/end stage (stages C/D). There are limited data on the prevalence of these stages in early adulthood and predictors of HF stage and symptoms in middle age. METHODS AND RESULTS: The CARDIA study (Coronary Artery Risk Development in Young Adults)-a cohort of generally healthy black and white men and women-collected phenotypic, echocardiographic, and outcomes data at the year 5 and year 30 examinations when participants were 22 to 37 and 47 to 62 years of age. Prevalence of HF stages was calculated and relationship of year 5 stage to year 30 classification and outcomes was assessed. At year 5, 2189 participants had complete data. Prevalence of HF stage A/B increased from 24% to 76% in black men, from 13% to 64% in white men, from 34% to 81% in black women, and from 13% to 56% in white women. Blacks were more likely to be in any stage or with morbidity at both time points because of higher risk factor prevalence. Of 33 participants with HF or HF deaths by year 30, 21 (64%) had been in stage A or B at year 5. Only 6 participants at year 5 in stage A (at risk) improved risk status at year 30. CONCLUSIONS: Risk for HF increased in participants from 1990 (age 22-37 years) to 2015 (age 47-62 years). Symptomatic HF or death from HF is associated with HF stage at 22 to 37 years of age. Blacks are disproportionately affected.