BACKGROUND: Suboptimal cardiovascular health (CVH) in pregnancy is associated with adverse maternal and offspring outcomes. To guide public health efforts to reduce disparities in maternal CVH, we determined the contribution of individual- and neighborhood-level factors to racial and ethnic differences in early pregnancy CVH. METHODS: We included nulliparous individuals with singleton pregnancies who self-identified as Hispanic, non-Hispanic Black (NHB), or non-Hispanic White (NHW) and participated in the nuMoM2b cohort study (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be). First-trimester CVH was quantified using 6 routinely assessed factors in pregnancy included in the American Heart Association Life’s Essential 8 score (0–100 points), in which higher scores indicate better CVH. Oaxaca-Blinder decomposition evaluated the extent to which racial and ethnic differences in CVH were explained by differences in individual- and neighborhood-level factors (age, socioeconomic