Do Puerto Rico Residents Owe US Tax?
Puerto Rico is considered an unincorporated United States territory, so the rules for residents of Puerto Rico are a little different than for residents of the 50 states. The determination of whether you owe US income taxes depends on your residency status and your income source.
In general, if you made your principal residence in Puerto Rico for a minimum of 183 days in the tax year, you are a bona fide resident of Puerto Rico and are exempt from submitting a United States federal income tax return. However, if you earn income from places not in Puerto Rico, are an employee of the federal government, or a military member, you do need to submit a tax return and pay tax on that portion of income. Even then, income from a source in Puerto Rico is still excluded.
If you do not meet the PR residency requirements, you must submit a tax return to report your income from any source. Therefore Puerto Ricans who move abroad or to the mainland must file US tax return.
There is one exception. This exception applies to those taxpayers who were residents of Puerto Rico for a minimum of two years prior to their move to the mainland. Income received from sources in Puerto Rico during the year the move occurred can be excluded from income reporting.
Whole Story at TFX.