Yes, REHABILITATION is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, H 4, A 1, B 3, I 1, L 1, I 1, T 1, A 1, T 1, I 1, O 1, N 1.

Is it a valid word?

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

the restoration of someone to a useful place in society
the conversion of wasteland into land suitable for use of habitation or cultivation
vindication of a person's character and the re-establishment of that person's reputation
the treatment of physical disabilities by massage and electrotherapy and exercises