Supreme Court
The heads of these departments are members of the Cabinet and serve at the pleasure of the President.
The Paperwork Reduction Act (1995) lists 19 enumerated ‘independent regulatory agencies.’ Heads of these agencies can only be removed for cause, and they are insulated fro presidential control to a significant degree.
These agencies are part of the Executive branch but exist outside of the federal executive departments. The heads of these agencies serve at the pleasure of the President and can be removed without cause.