Multimorbidity, or the presence of two or more co-occurring chronic medical conditions, is extremely prevalent within the United States (US), with disproportionately high incidence rates in individuals with minoritized identities. Sleep disturbances are an empirically supported risk factor contributing to disease status and maintenance throughout the lifespan. Given this, this study examines the relationship between disturbed sleep and multiple chronic conditions (MCCs) in adults using cross-sectional data from (n = 1013) participants enrolled in the Survey of Midlife Development in the US Study (MIDUS-2). Participants within this study were predominantly female (54.9%), white (93.2%), middle-aged (M_AGE = 58 years old), and experienced multimorbidity (56.6%) by having two or more (M_CHRON = 2.25) chronic health conditions in the past year. A negative binomial regression indicated that sleep disturbances significantly predict the number of chronic health conditions, with sleep-disturbed individuals reporting a 41% increase in reported health conditions (IRR = 1.407, p < 0.001). Findings suggest that disturbed sleep is significantly related to disease presence in aging populations and should be addressed through early intervention to mitigate negative health consequences.