U.S. citizens must obtain a tourist visa to enter Turkey for a maximum of 90 days (multiple entry). After the 90-day period has lapsed, you will be required to buy a new visa or obtain permanent or long-term residency permit.
Turkey has an e-visa (electronic visa) and it is available at any time. Also, you obtain the visa after filling out all the information including identity, passport and travel dates and paying the visa fee online.
Above all, this electronic visa is only valid for tourism or commerce.
For instance, the fees for e-Visas obtained via the website are lower than the fees for visas obtained upon arrival to Turkish airports.
It used to be difficult for a foreigner to establish full-time residency in Turkey, but it was made much easier in 2014. Now it’s even possible to obtain residency through the purchase of real estate.
Still, Turkey may be best enjoyed as a part-time retirement option. If you live here more than six months of the year, you become liable to the Turkish authorities for tax on your worldwide income.
Residency in Turkey can lead to a second passport and dual citizenship in this country, but there are several requirements, including “adequate command” of the Turkish language.