Is it insurance fraud if you pay someone's deductible?

Yes in some states it is considered fraud and illegal. Texas is one state. As a contractor if I turn in a final bill to an insurance company and it states that I paid the homeowners deductible, portion of deductible or gave them a sign allowance for putting a sign in their yard ( this is thought of as a clever way to hide the payment of the deductible), the insurance company will reduce the final payment by that amount. If you leave it off of the invoice it does not honestly show the expenses.