A consistent set of 32 group additive values is determined for the Arrhenius parameters of carbon-centered radical addition to oxygenates and the reverse -scission of oxygenate compounds, covering a wide temperature range (300-2500 K). These values are derived based on a training set of 66 reactions for which the Arrhenius parameters are calculated using the CBS-QB3 method in the high-pressure limit, including corrections for hindered internal rotation. The accuracy of the model is established by comparing model predictions with an ab initio (AI) validation set containing 24 reactions. The mean factor of deviation between the group additively calculated and the AI rate coefficients is 3, for both radical additions and -scissions. Therefore, the developed group additive model, constituting an extension of the existing model for carbon-centered radical additions and -scissions of hydrocarbons, can be safely applied for an accurate prediction of kinetics of the corresponding reactions involving oxygenate compounds. (c) 2015 American Institute of Chemical Engineers AIChE J, 62: 802-814, 2016