The US Open play-off is the only major in which it is an extra 18 holes on Monday.
If players are still tied after that fifth round, they would then go into a sudden-death play-off from the 91st hole.
US Open play-off tee time
Monday June 19, 2017: 6pm (UK time)
If we don’t get a play-off on Monday, it will be the longest stretch without extra holes in US Open history.
Consecutive U.S. Opens without a playoff: 8. We have never gone 9 in a row without one. #USOpen
— Justin Ray (@JustinRayGC) June 18, 2017