CMSY-ICCAT is an “ICCAT-friendly” version of the original CMSY R code by Froese et al. (2016) to facilitate comparison of CMSY results with outputs conventionally produced by Bayesian surplus models. Among the newly implemented features are: (1) a plot comparing normalized trends of CMSY biomass projection to observed and predicted CPUE from the CMSY.BSM, (2) plots comparing CMSY distributions of for K, r, Bcur/BMSY and Fcur/FMSY to the corresponding posteriors from the CMSY.BSM, as well as priors for K an r and (3) a Kobe-type biplot that allows comparing the CMSY and CMSY.BSM trajectories of the ratios F/FMSY (y-axis) over B/BMSY (x-axis), with uncertainties for the assessment year final illustrated as kernel density plots denoting the 50%, 80% and 95% credibility intervals. The original CMSY version by Froese et al. (2016) applies a Schaefer model that is modified to account for impaired recruitment by resembling a hockey-stick function of B/BMSY. Although this adjustment has showed several merits (Froese et al. 2016), for the purpose of comparability, the current version CMSY_ICCAT version applies a conventional Schaefer model for the purpose of comparability.