Nearly half of all US workers have access to an employee assistance plan (EAP). At the same time, most large US employers also purchase health benefits for their employees, and these benefits packages typically include behavioral health services. There is some potential overlap in services covered by the EAP and the health plan, and some employers choose to purchase the two jointly as an 'integrated product'. It is not clear whether EAP services substitute for outpatient behavioral health care services covered by the health plan.To evaluate how the number of EAP visits covered affects the use of regular outpatient behavioral health care (number of visits, and total spending), in an integrated product setting.Analysis of claims, eligibility and benefits data for 26,464 users of behavioral health care for the year 2005. For both EAP and regular behavioral health care, the individuals were enrolled with Managed Health Network (MHN), a large national specialty insurance plan. Multivariate regression analyses were performed to investigate the determinants of the number of regular outpatient visits, and spending for regular outpatient care. To address skewness in the dependent variables, the estimation used generalized linear models with a log link. A limited instrumental variable analysis was used to test for endogeneity of the number of EAP visits covered.Nearly half the enrollees in this sample were in employer plans that allowed 4-5 EAP visits per treatment episode, and 31% were allowed 3 EAP visits per year. Having an EAP visit allowance of 4-5 sessions per episode predicts fewer regular outpatient visits, compared with having an allowance of 3 sessions per year. More generous EAP allowances also reduce payments for outpatient care, with one exception.Greater availability of EAP benefits appears to reduce utilization of regular outpatient care, supporting the idea that the two types of care are to some extent perceived as substitutes. One limitation of this study is its cross-sectional nature, since the relationships observed could reflect the effect of other unmeasured variables. Also, the data are from a single managed behavioral health organization, limiting generalizability somewhat, although many employers are represented in the data.The results should discourage employers from either eliminating EAP benefits as duplicative, or replacing behavioral health benefits with an expanded EAP. Patients appear to perceive that EAP services offer something distinct from regular outpatient care.Future studies should see whether these results are reproduced, ideally by looking at employer plans with a wider range of EAP visit allowances.