This study examined whether substance abuse patients who live farther from their source of outpatient mental health care were less likely to obtain aftercare following an inpatient treatment episode. For those patients who did receive aftercare, distance was evaluated as a predictor of the volume of care received. A national sample of 33,952 veterans discharged from Department of Veterans Affairs (VA) inpatient substance abuse treatment programs was analyzed using a two-part choice model utilizing logistic and linear regression. Patients living farther from their source of outpatient mental health care were less likely to obtain aftercare following inpatient substance abuse treatment. Patients who traveled 10 miles or less were 2.6 times more likely to obtain aftercare than those who traveled more than 50 miles. Only 40% of patients who lived more than 25 miles from the nearest aftercare facility obtained any aftercare services. Patients who received aftercare services had fewer visits if they lived farther from their source of aftercare. Lack of geographic access (distance) is a barrier to outpatient mental health care following inpatient substance abuse treatment, and influences the volume of care received once the decision to obtain aftercare is made. Aftercare services must be geographically accessible to ensure satisfactory utilization.