This paper develops a prototype macroeconomic model for assessing monetary and fiscal policy in a small emerging-market open economy. We then use this model to evaluate the performance of monetary and fiscal policies in Malaysia between 2005 and 2021. The paper presents a discussion of key macroeconomic variables over this period. Bayesian estimation is applied to the model to obtain parameter values governing dynamic adjustments, and we identify which variables played pivotal roles in overall macroeconomic volatility during the sample period. Optimal policy designs for both monetary policy and fiscal transfers are determined, and their performance is assessed relative to the historical base paths. Additionally, we demonstrate that the base paths are closer to the optimal paths compared to non-intervention policies for fiscal transfers and a pure inflation-targeting rule for the Taylor Rule, without an output-gap response.