Objective Despite race- and sex-specific differences in risk of heart failure (HF), there are limited data comparing the contribution of major modifiable risk factors to the population burden of HF in each race-sex group. In addition, studies have not used a competing risk framework to account for death in the absence of HF, to provide a more accurate risk estimate for each risk factor. We determined the contribution of modifiable risk factors, specifically hypertension, diabetes, obesity, current smoking, and hyperlipidemia, to the population burden of HF, as measured by population attributable fraction (PAF), stratified by race and sex. Methods A pooled cohort was created using harmonized data from six longitudinal US-based cohorts (Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Heart Study starting from 1970, Framingham Offspring Study, and the Multi-Ethnic Study of Atherosclerosis). Baseline measurements of the risk factors were used to determine prevalence. Relative risk of incident HF for each risk factor was determined using a piecewise constant hazards model adjusted for age, education, other modifiable risk factors, and the competing risk of non-HF death. PAF for HF was then calculated for each risk factor in each race-sex group. Results Hypertension had the highest adjusted PAF in black men (28.3%, 95% CI 18.7, 36.7%) and black women (25.8%, 95% CI 16.3, 34.2%). In contrast, obesity had the highest adjusted PAF in white men (21.0%, 95% CI 14.6, 27.0%) and white women (17.9%, 95% CI 12.8, 22.6%). Diabetes disproportionately contributed to HF in black women (PAF 16.4%, 95% CI 12.7, 19.9%). Current smoking made a modest contribution and hyperlipidemia contributed minimally to HF risk. The cumulative PAF for all risk factors was highest in black women (51.9%, 95% CI 39.3, 61.8%) and lowest in white women (39.3%, 95% CI 33.9, 44.4%). Conclusions Our findings extend insights into the contribution of modifiable risk factors to population HF burden by using a competing risk model and providing race and sex-specific contemporary PAF estimates (Figure 1). Our results highlight the growing impact of hypertension and diabetes on HF burden, especially in black women. These results can guide public health policies aimed at reducing the population burden of HF. Despite race- and sex-specific differences in risk of heart failure (HF), there are limited data comparing the contribution of major modifiable risk factors to the population burden of HF in each race-sex group. In addition, studies have not used a competing risk framework to account for death in the absence of HF, to provide a more accurate risk estimate for each risk factor. We determined the contribution of modifiable risk factors, specifically hypertension, diabetes, obesity, current smoking, and hyperlipidemia, to the population burden of HF, as measured by population attributable fraction (PAF), stratified by race and sex. A pooled cohort was created using harmonized data from six longitudinal US-based cohorts (Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Heart Study starting from 1970, Framingham Offspring Study, and the Multi-Ethnic Study of Atherosclerosis). Baseline measurements of the risk factors were used to determine prevalence. Relative risk of incident HF for each risk factor was determined using a piecewise constant hazards model adjusted for age, education, other modifiable risk factors, and the competing risk of non-HF death. PAF for HF was then calculated for each risk factor in each race-sex group. Hypertension had the highest adjusted PAF in black men (28.3%, 95% CI 18.7, 36.7%) and black women (25.8%, 95% CI 16.3, 34.2%). In contrast, obesity had the highest adjusted PAF in white men (21.0%, 95% CI 14.6, 27.0%) and white women (17.9%, 95% CI 12.8, 22.6%). Diabetes disproportionately contributed to HF in black women (PAF 16.4%, 95% CI 12.7, 19.9%). Current smoking made a modest contribution and hyperlipidemia contributed minimally to HF risk. The cumulative PAF for all risk factors was highest in black women (51.9%, 95% CI 39.3, 61.8%) and lowest in white women (39.3%, 95% CI 33.9, 44.4%). Our findings extend insights into the contribution of modifiable risk factors to population HF burden by using a competing risk model and providing race and sex-specific contemporary PAF estimates (Figure 1). Our results highlight the growing impact of hypertension and diabetes on HF burden, especially in black women. These results can guide public health policies aimed at reducing the population burden of HF.