Drawing from Lyapunov stability theory, a single input single output model reference adaptive control (MRAC) system using a unified format is researched. A novel design approach is proposed, wherein the control system utilizes the measured value of the model output, thus circumventing issues associated with the unmeasured output differential value of the controlled plant. Because of taking state variables from the model, the system’s resilience against disturbances is notably strengthened. In contrast to the augmentation error signal design method, this approach allows for the derivation of the adaptive control law without the need for an augmentation error signal. Consequently, there is a reduction in the number of adjustable parameters, and the elimination of a set of filters significantly simplifies the system structure, rendering it more amenable to engineering implementation. This streamlined approach promises enhanced efficiency and ease of deployment in practical applications.