This article develops a model of how customers with prior experiences and expectations assess service performance levels, overall service quality, and service value. The model is applied to residential customers' assessments of local telephone service. The model is estimated with a two-stage least squares procedure through survey data. Results indicate that residential customers' assessments of quality and value are primarily a function of disconfirmation arising from discrepancies between anticipated and perceived performance levels. However, perceived performance levels also were found to have an important direct effect on quality and value assessments.