We explore the potential implications of the Generative Pre-trained Transformer (GPT) model and related technologies for the US labor market. Using the new rubric, we evaluate occupations based on their correspondence to GPT capabilities, including human expertise and classifications from GPT-4. Our findings indicate that approximately 80% of the US workforce could have at least 10% of their work tasks affected by the introduction of GPT, while about 19% of workers could see at least 50% of their tasks affected. The impact extends across all pay levels, with higher-paying jobs potentially more exposed. Namely, the impact is not limited to industries with higher recent productivity growth. We conclude that generative pretrained transformers exhibit characteristics of general purpose technologies (GPTs), suggesting that these models could have significant economic, social, and political implications.