Indiana Code Title 34. Civil Law and Procedure § 34-18-10-9

Sec. 9. Within fifteen (15) days after the chairman is selected, both parties shall select a health care provider and the parties shall notify the other party and the chairman of their selection.  If a party fails to make a selection within the time provided, the chairman shall make the selection and notify both parties.  Within fifteen (15) days after their selection, the health care provider members shall select the third member within the time provided and notify the chairman and the parties.  If the providers fail to make a selection, the chairman shall make the selection and notify both parties.