We propose a simple and accurate model for state-specific dissociation rate coefficients based on the widely used Treanor–Marrone model. It takes into account the dependence of the parameter in the Treanor–Marrone model on temperature and vibrational level and can be used with arbitrary vibrational ladder. The model is validated by comparisons with state-specific dissociation rate coefficients of O2 and N2 obtained using molecular dynamics, and its good accuracy is demonstrated. Twotemperature dissociation rate coefficients are derived averaging the state-specific non-equilibrium factors with different vibrational distributions. The two-temperature rate coefficients are compared with those given by the empirical Park model and coefficients extracted from shock-tube measurements.