Ind. Code § 22-3-9-5
Any contract, rule, regulation, bylaw, or device whatsoever, the purpose, intent, or effect of which would be to enable any employer to exempt himself or itself from any liability created by this chapter, shall to that extent be void; provided, that in any action brought against any such employer under or by virtue of any of the provisions of this chapter, such employer may set off therein by special plea any sum such employer has contributed or paid to any insurance, relief benefit, or indemnity for and on behalf of such injured employee that may have been paid to him or to the person entitled thereto on account of the injury or death for which said action is brought, but in no event shall the amount of such setoff exceed the amount paid to such employee or other person entitled thereto out of such insurance, relief benefit, or indemnity fund.
IC 22-3-9-5