We use longitudinal linked employer-employee data and find that the probability of participating in firm-sponsored classroom training diminishes rapidly for workers aged 45 years and older. Although the standard human capital investment model predicts such a decline, we also consider the possibility that returns to training decline with age. Taking into account endogenous training decisions, we find that the training wage premium diminishes only slightly with age. However, estimates of the impact of training on productivity decrease dramatically with age, suggesting that incentives for firms to invest in classroom training are much lower for older workers.