The two-dimensional potential energy surfaces for the He-HCN, Ne-HCN, Ar-HCN, and Kr-HCN complexes are presented. Calculations have been performed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD(T)] and the augmented correlation-consistent polarized triple-zeta basis set (aug-cc-pVTZ) with an additional (3s3p2d2f1g) set of bond functions. The potentials have been used to find the vibration-rotation energies of the four complexes and their deuterated analogs. The frequencies of rotational or rovibrational transitions found for He-HCN and Ar-HCN are in very good agreement with the experimental results. Good agreement is also obtained with the experimental rotational transition frequencies for Kr-HCN. For Ne-HCN, on the other hand, the agreement with the experimental data is not as good, but can be improved by using larger basis sets.