Yes, MAVERICKS is a Scrabble word!

Letter values in Scrabble US: M 3, A 1, V 4, E 1, R 1, I 1, C 3, K 5, S 1.

Is it a valid word?

MAVERICKS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

someone who exhibits great independence in thought and action
an unbranded range animal (especially a stray calf); belongs to the first person who puts a brand on it