A widely and readily applicable covariance structure modeling approach is outlined that allows point and interval estimation of scale reliability with fixed components. The procedure employs only linear constraints introduced in a congeneric model, which after reparameterization permit expression of composite reliability as a function of appropriate parameters. Unlike the popular Cronbach's coefficient alpha that already at the population level is generally a misestimator of scale reliability, this method is based on the formal definition of the reliability coefficient. The proposed approach is illustrated by means of a numerical example.