The implementation of two-photon transition moments is described for the hierachy of coupled cluster models CCS, CC2 and CCSD and applications are reported for the two-photon transition probability rate constants for transitions from the ground state to the first excited S-1(e) state in helium and to the lowest D-1(e) and S-1(e) states in neon and argon. At the CCSD level the rate constant for the D-1(e) transition in argon is in good agreement with the experimental rate constant and also with a recent MCSCF calculation.