This prospective study examined the influence of caregiving variables on the development of problematic alcohol use among family members of patients admitted to an urban Level I trauma center. Data were collected from 124 caregivers 48 hrs after initial hospitalization of their family member. The final sample included 81 participants (24.6% male; Mage = 47.8) who completed their follow-up assessment at 6 months. Hierarchical linear and logistic regression analyses assessed increases in consumption and odds of a positive screen for problematic alcohol use in association with caregiver burden, actual time spent in the caregiving role, and caregiving differential (i.e., anticipated time spent caregiving at baseline in relation to actual time caregiving at 6 months). At 6 months, 24.7% of caregivers screened positive for problematic alcohol use. Results uniquely highlighted caregiving differential as a significant predictor of both increases in general alcohol consumption (ΔR2 = .06, p < .01) and odds of screening positive for problematic alcohol use at 6 months (Odds Ratio = 1.05, 95% CI [1.02–1.09]). More specifically, our adjusted model found that providing 10% more time caregiving, relative to expectations at baseline, was associated with an increase in the probability of problematic alcohol use by 22% (95% CI: 8–37%) at 6 months. These results suggest that a discrepancy in expectations regarding anticipated time caregiving and actual time caregiving, rather than solely the amount of caregiving or perceived caregiver burden, may be an important predictor of caregiver alcohol use 6 months after a family member’s ICU hospitalization.