Yes, you can. Even after you move abroad, U
Yes, you can. Even after you move abroad, US citizens must still file a Federal Return if they are receiving income. Fortunately there are some big exclusions and credits in place to limit (or even eliminate) this tax liability. These include the Foreign Earned Income Exclusion and the Foreign Tax Credit.
Together, these credits will make your US liability much lower than when you were living in the States. In fact, with the Foreign Tax Credit, you could even get a credit on your US taxes to carry forward on next year’s taxes (this would happen if you are paying more in tax to Panama than you would have been to the US).