I'm applying for a 60 day tourist visa from the US. I'm buying a round trip ticket with a return date 71 days from the date I depart. I plan to extend before my 60 days are up. Will that be an issue when I arrive in Thailand going through immigration at the airport, because my departure is beyond 60 days?
TLDR : Answer Summary
Entering Thailand with a 60-day tourist visa and a 71-day return ticket should not cause problems with Thai immigration as long as you have a valid visa. The main concern might be at the US airport where airline staff check your travel documents. Be sure to print and present your eVisa and confirm your return flight details with the airline to avoid issues.