Article II, Section 1, Clause 7: Compensation and Emoluments

The President shall, at stated Times, receive for his Services, a Compensation, which shall neither be increased nor diminished during the Period for which he shall have been elected, and he shall not receive within that Period any other Emolument from the United States, or any of them.

This is a straightworward clause, based on similar provisions regarding judicial salaries. An 1869 opinion by the Attorney General held that a tax specifically on a Presidential salary would violate this clause unless it went into effect only at the end of the President’s term.

This clause would forbid a former state governor who is elected President from continuing to collect a state pension so long as he remains President. Likewise, a retired military officer who was elected President could not collect his federal pension so long as he was serving as President. A change in Presidential salary can go into effect only at the end of the sitting President’s term.