Version 2 of the Regeneration Establishment Model is part of version 6 of the Prognosis Model for Stand Development. The regeneration model predicts results of regeneration harvests for most site and stand conditions found in the Northern Rocky Mountains. The model is based on analysis of 12,128 1/300-acre plots sampled in forests of western Montana, and central and northern Idaho, and includes the influence of western spruce budworm (Choristoneura occidentalis Freeman) defoliation on regeneration success. Direct linkage to the Prognosis Model allows projections from one rotation to the next. Both even age and uneven age management can be simulated. Model characteristics, prescription options, program control, and regeneration summaries are discussed.