YES

Yes, YES is a Scrabble word!

Letter values in Scrabble US: Y 4, E 1, S 1.Y 4 · E 1 · S 1

Is it a valid word?

• Scrabble US: valid, 6 points.Scrabble USYour dictionary · Change (go to the dictionary switch)Valid · 6 points
• Scrabble UK: valid, 6 points. Make Scrabble UK your dictionary.Scrabble UKYour dictionary · ChangeValid · 6 points
• Words with Friends: valid, 5 points. Make Words with Friends your dictionary.Words with FriendsYour dictionary · ChangeValid · 5 points