Indiana Code Title 34. Civil Law and Procedure § 34-18-10-10

Sec. 10. Within ten (10) days after the selection of a panel member, written challenge without cause may be made to the panel member.  Upon challenge or excuse, the party whose appointee was challenged or dismissed shall select another panelist.  If the challenged or dismissed panel member was selected by the other two (2) panel members, the panel members shall make a new selection.  If two (2) such challenges are made and submitted, the chairman shall within ten (10) days appoint a panel consisting of three (3) qualified panelists and each side shall, within ten (10) days after the appointment, strike one (1) panelist.  The party whose appointment was challenged shall strike last, and the remaining member shall serve.