The steady state cooling rates for collisionally excited CO have been recalculated using recent cross sections of Schinke et al. (1985) and Flower and Launay (1985). Despite large differences in particular rate coefficients, it is found that the original calculations of McKee et al. (1982) for hot gas (T equal to or greater than 100 K) are nearly correct, so that the level populations and cooling rates are not grossly affected by the changes. CO masers are slightly less prevalent than previously thought. In the lower temperature limit (T equal to or greater than 100 K), the cooling rates are insensitive to the discrepancies between different theoretical cross sections. 19 references.