Retirement overseas and taxes

The norm could be very different from country to country. Retirement income is usually not taxed, is possible that you will owe US taxes on social security but not in the country where you reside.
Social security is excuse from state tax if you live overseas. If you don’t have rental properties in your last state then for most states you will exempt from state filing.

You must note that if you are a U.S citizen or a legal alien of the U.S.A and live in Colombia, the U.S.A expat tax in Colombia is based on your worldwide income. You must file taxes. A U.S gain for all the time you were living in Colombia.