What do I need to prepare for a week-long trip back to the U.S. as a U.S. citizen living in Thailand on a retirement visa?

A U.S. citizen residing in Thailand on a retirement visa, planning to return to the U.S. for a week, only needs a valid U.S. passport; no visa is required for short visits. Community members confirm that a passport suffices for entry and exit. There are informal discussions about the high costs of living in the U.S. compared to Thailand, highlighting potential culture shock upon returning.