Yes, VESTING is a Scrabble word!

Letter values in Scrabble US: V 4, E 1, S 1, T 1, I 1, N 1, G 2.

Is it a valid word?

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

provide with power and authority
place (authority, property, or rights) in the control of a person or group of persons
become legally vested
clothe oneself in ecclesiastical garments
clothe formally; especially in ecclesiastical robes