Objectives: To determine the effect of integrating informal caregivers into discharge planning on postdischarge cost and resource use in older adults.; Design: A systematic review and metaanalysis of randomized controlled trials that examine the effect of discharge planning with caregiver integration begun before discharge on healthcare cost and resource use outcomes. MEDLINE, EMBASE, and the Cochrane Library databases were searched for all English-language articles published between 1990 and April 2016.; Setting: Hospital or skilled nursing facility.; Participants: Older adults with informal caregivers discharged to a community setting.; Measurements: Readmission rates, length of and time to post-discharge rehospitalizations, costs of postdischarge care.; Results: Of 10,715 abstracts identified, 15 studies met the inclusion criteria. Eleven studies provided sufficient detail to calculate readmission rates for treatment and control participants. Discharge planning interventions with caregiver integration were associated with a 25% fewer readmissions at 90 days (relative risk (RR) = 0.75, 95% confidence interval (CI) = 0.62-0.91) and 24% fewer readmissions at 180 days (RR = 0.76, 95% CI = 0.64-0.90). The majority of studies reported statistically significant shorter time to readmission, shorter rehospitalization, and lower costs of postdischarge care among discharge planning interventions with caregiver integration.; Conclusion: For older adults discharged to a community setting, the integration of caregivers into the discharge planning process reduces the risk of hospital readmission.