The Dominican is correct and prat985 is dead wrong. If you are a US citizen, you will not pay tax in the USA generally speaking. You will be a resident of Panama, and that will automatically qualify you for the big exemption. Based on the Copa Captain wages, you will not owe Uncle Sam. Also, you can spend over 30 days in the USA per year and this scenario will not change. If you have other sources of income, then generating a USA tax liability is possible. As always, consult your tax guy though.