Acculturation stress, a type of sociocultural stress, is positively associated with insomnia among Latinxs; however, the mechanisms of this association remain elusive. We tested the indirect effects of acculturation stress on insomnia through rumination and alcohol use, two coping strategies associated with insomnia, and explored these effects in gender-stratified models among Latinxs. We analyzed cross-sectional data from 187 Latinxs participating in the Latino Sleep and Health study in New York City in 2016-2019. We conducted bias-corrected boot-strap tests of mediation with case resampling (1,000 replications) in aggregate and gender-stratified models. Acculturation stress and insomnia were measured continuously using the Hispanic Stress Inventory and Insomnia Severity Index (ISI). Rumination was measured using a subscale of the Ruminative Response Scale. The Quantity-Frequency Index was used to measure alcohol use. Covariates included age, New York City poverty threshold, and perceived stress. Participants were Mage 37.43 (SD = 13.67). Most participants were women (64.17%). The average ISI was 6.65 (SD = 5.51). The indirect effect of acculturation stress on insomnia through rumination was statistically significant (b = 0.02, 95% BCa CI [0.01, 0.03]). Among women, this indirect effect had slightly larger coefficients than among men (b = 0.02, 95% BCa CI [0.01, 0.04]; b = 0.01, 95% BCa CI [0.004, 0.04]). Alcohol use was not a statistically significant mediator (b = -0.001, 95% BCa CI [-0.004, 0.0002]). These findings suggest that psychological interventions focused on reducing rumination in response to acculturation stress may promote healthy sleep among Latinxs, particularly among Latina women. Future studies should use longitudinal study designs to determine the causal relationships among these variables. (PsycInfo Database Record (c) 2024 APA, all rights reserved).