I thought this was an appropriate question as Arizona and Michigan voters head to the polls today.  The answer comes from Scholastic.com.

Do U.S. territories vote in the primaries?

Yes. A territory is a part of the United States that has its own government but is not considered a state. Voters in U.S. territories do hold primaries and caucuses to help select the party nominees for President. But because territories are not states, their citizens do not get to vote for the President in the general election. These include American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands.