Yes, a US citizen can live in St. Maarten, but the process is significantly easier on the Dutch side (Sint Maarten) than on the French side (Saint-Martin). Thanks to the Dutch-American Friendship Treaty (DAFT), US citizens have a simplified path to residency that does not require a traditional work permit if they are self-employed or starting a business. Under the treaty, Americans can apply for a residency permit relatively easily compared to other Caribbean nations. However, if you are looking to be employed by a local company, that company must still prove they couldn't find a local candidate for the job. To live there permanently, you will need to provide proof of a clean criminal record, health insurance, and sufficient financial means to support yourself. For retirees, there is a specific "pensionado" status that offers favorable tax rates. Note that the French side follows stricter European Union immigration rules, which are much harder for non-EU citizens to navigate.