Indiana Code Title 3. Elections § 3-8-2-20

Sec. 20. (a) A person who files a declaration of candidacy under this chapter may, at any time not later than noon eighty-one (81) days before the date set for holding the primary election, file a statement with the same office where the person filed the declaration of candidacy, stating that the person is no longer a candidate and does not wish the person's name to appear on the primary election ballot as a candidate.

(b) A candidate who is disqualified from being a candidate under IC 3-8-1-5 must file a notice of withdrawal immediately upon becoming disqualified.  The filing requirements of subsection (a) do not apply to a notice of withdrawal filed under this subsection.

(c) A candidate who has moved from the election district the candidate sought to represent must file a notice of withdrawal immediately after changing the candidate's residence.  The filing requirements of subsection (a) do not apply to a notice of withdrawal filed under this subsection.