Yes, INSURANCE is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, S 1, U 1, R 1, A 1, N 1, C 3, E 1.

Is it a valid word?

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

promise of reimbursement in the case of loss; paid to people or companies so concerned about hazards that they have made prepayments to an insurance company
written contract or certificate of insurance
protection against future loss

Also: insurance policy.