Travel Visas
If your travel has been mostly within the US and Europe, this is another area you may overlook. Luckily, many countries either don’t require travel visa for Americans or are relatively easy to obtain online. Countries like New Zealand, Australia, Cambodia and Laos all allow various forms of electronic visa, saving you the hassle of having to give up your passport in the application process or stopping by the consulate. The two major exceptions where travel visas are a pain to get are China and Russia. If you plan to visit these countries, allow plenty of time to apply for travel visa. The best resource to check travel visa requirement is the US government travel website below. Follow this up with checking the government website of the country you’re visiting, and you’ll be all set.
https://travel.state.gov/content/travel/en/us-visas.html
Make sure your passport is valid beyond six months AFTER you return to the US. You will not be allowed to enter a country if your passport expires within 6 months from the date of entry. This is true with most, if not all, countries.