This paper investigates whether access to a general-purpose large language model (LLM) improves physicians’ clinical reasoning across diverse healthcare contexts, as well as the possible implications of using an LLM in healthcare settings. Using a randomized controlled trial with 249 physicians in Indonesia, Kenya, and the Netherlands, the study finds that LLM access enhances performance on standardized clinical vignettes in all three countries. The magnitude of improvement varies, with the largest gains observed in Kenya (+18%), followed by Indonesia (+10.7%) and the Netherlands (+7.2%).