Make sure your passport is up to date. Plan early because it can take several weeks to renew a passport. You can download forms and learn more at travel.state.gov . There are several online services that will help you renew your passport quickly, for a fee. Get your shots.
Many foreign countries require or recommend that visitors have certain vaccinations.
Read the fine print on your insurance. Your health insurance may not apply when you travel outside of the country. A trip to the doctor's office in another state may also be out of your policy's reach. A handful of companies including International SOS offer travel insurance and access to a network of doctors around the world. The fee varies according to your age and health.