This research explores the potential effects of large language models (LLMs), like GPTs, on the U.S. workforce. It uses a new method involving both human experts and GPT-4 to determine how many job tasks could be affected by LLMs, including when paired with additional software. The findings indicate a significant portion of the workforce may see at least some tasks impacted, with higher-wage jobs potentially having greater exposure, suggesting LLMs could be a general-purpose technology with broad economic and societal implications.