This study integrates and expands two models of organizational support perceptions, job attitudes, effort, and employee behavior (i.e., Brown & Leigh, 1996; Netemeyer, Boles, McKee, & McMurrian, 1997). An integrated model was hypothesized, in which Perceived Organizational Support and Perceived Opportunity for Reward impacted job satisfaction, organizational commitment, and job involvement, which in turn influenced effort (work intensity and time commitment), which subsequently impacted Organizational Citizenship Behaviors (OCBs) and in-role performance. Employee – supervisor dyads were surveyed (n = 279), and structural equation modeling was used to test the hypothesized model and several alternative models. Results indicated that the hypothesized model fit the data well, and fit better than several a priori developed alternatives. Inspection of specific parameter estimates indicated that POS and POR impacted job satisfaction, job involvement, and affective organizational commitment. In turn, job satisfaction influenced work intensity, whereas job involvement influenced time commitment. Contrary to predictions, employee effort did not significantly impact in-role performance or OCBs. Limitations, contributions, and practical implications are discussed.