TSA has issued Title 49 of the United States Code of Federal Regulations Part 1552 that prohibits a flight school from providing flight training in an aircraft or aircraft simulator to non US Citizens unless the flight school or the candidate submits certain information to TSA. TSA will then determine that the candidate is not a threat to aviation or national security.
Under this Rule, there are four categories of candidates:
Category 1 is for pilots who do not have a heavy type rating (over 12,500 lbs.) on their FAA or foreign airman certificate. Initial Type Rating TSA Approval Process
Category 2 is for pilots who do have a heavy type rating (over 12,500 lbs.) on their FAA or foreign airman certificate, but are training in an aircraft they are not currently qualified in. Initial Type Rating TSA Approval Process
Category 3 is for pilots training in any aircraft with a MTOW of 12,500 lbs. or less. (Note: in many cases Category 3 is waived and no TSA application is required. Check with your learning center).
Category 4 is for pilots who are training in aircraft they are already qualified in, for example recurrent training. No fingerprints are required. Recurrent TSA Approval Process