Over 35 years of behavioral research have shown contingency management systems in the classroom are highly effective for treating children with behavior problems. Questions remain if such systems can be enhanced by the functional assessment process. This case study looks at a nine-year-old child with oppostional behavior who was on a contingency management program. After a though functional assessment the author determined that poor sleep patterns contributed to poor performance on the token system the following morning. This post-hoc analysis of the data conformed to a reversal design. The program showed a functional relationship between neutralizing sleep difficulty and increasing of point earned and the decreasing of episodes of response cost. Keywords: establishing operations, enhancing standard interventions, sleep. ********** Since its first use by O'Leary, and Becker, (1967), competent implementation of contingency management systems has been extremely effective in changing most behavioral challenges in the classroom (Axelrod, 1983a, b; Barbetta, 1983a, 1983b; Bongiovanni, 1979; Filcheck & McNeil, 2004; Wolery, Bailey, & Sugai, 1988). For example, Barbetta (1983a, b) used a contingency management system in the form of token reinforcement and response cost (loss of tokens) to reduce impulsivity in children with behavior disorders. MTA (Multimodal Treatment Study for Attention-Deficit Hyperactivity Disorder, 1999) Cooperative Group (1999) used contingency management programs for ADHD children to contrast with medication and Pelham, Greiner, & Gnagy, (1997) used such a program in their summer camp program for ADHD children. In addition, Walker and Buckley (1972, 1974) and O'Connor, Struck, and Wyne (1979) used a similar point system with response cost in the Engineered Learning Program, which is one of the few programs empirically validated for use with children in emotional support classes. Contingency management systems have been so successful that some have question if functional analysis can add anything to this type of intervention. For example, Twernbold-Schill, Kratochwill and Elliot (1998) selected twenty preschool children in a Head Start class and randomly assigned them into two groups. They compared a standardized technological intervention package (group contingencies) to a functionally based intervention. There was no significant difference found between the two interventions with respect to outcomes. The functional assessment group achieved higher customer satisfaction rating. From such research, Branden and Kratochwill (1997) argued that prescribed interventions without a functional behavioral assessment can be more efficient under one of the following three conditions (a) assessment costs can exceed treatment costs, (b) consequences of delaying treatment are minimal, and (c) no link between selected treatment and function have been found. Such calls for parametric analysis are premature in this author's opinion because only one study demonstrates conditions under which functional behavior assessment has enhanced treatment (Hayes et. al, 1987). With all of this attention paid to functional analysis, it remains surprising that so few program have shown that functional analysis can enhance standard treatment packages. One example, of the use of functional analysis to enhance treatment outcomes is in the case of changing establishing operations (Michaels, 1993). Ray and Watson (2001) found that for one child, out-of-seat behavior occurred in only 32.5% of the measured intervals. The authors determined that both escape and access to tangible reinforcers maintained the child's behavior. More importantly, on days in which the child slept less than 5 hours the previous night, out-of-seat behavior increased to 57.5% of the intervals and only access to tangibles maintained that behavior. In this case, sleep deprivation clearly served as an EO to increase the effectiveness of tangible reinforcers. …