Provided is a process for preparing carbonylated derivatives of amino- and haloamino-1,3,5-triazines by contacting the 1,3,5-triazine, carbon monoxide and a metal catalyst system containing a metal promoter for promoting carbonylation, at a temperature carbon monoxide pressure and length of time sufficient to carbonylate at least a portion of the amino and/or haloamino groups of the 1,3,5-triazine. The product resulting from contacting these components is an isocyanate functional 1,3,5-triazine; however, the carbamate functional derivative can be readily produced by contacting these components in the further presence of a hydroxy compound, or by post-reacting the isocyanate functional product with such hydroxy compound.