20880302_ferences__July_2014_FIDE_Laws___FIDE_rule
[0] 8. [USCF rule] If a player does not replace a pawn on the last rank with a promotion piece and presses the clock, the opponent may immediately press the clock or stop the clock and summon a director (advisable in an increment time control). The player does not lose the right of choice of promotion piece. [FIDE rule] 
If the player moves a pawn to the last rank and presses the clock without replacing the pawn with a promotion piece, the player has completed an illegal move (see item 5 for implications) and the pawn shall be replaced by a queen of the same color as the pawn. The player has no choice in the promotion piece, even if promoting the pawn to a queen causes stalemate.
The United States Chess Federation - USCF - FIDE Rule Differences (July 2014 FIDE Laws)
FIDE rule