422.3  Definitions controlling chapter.
  For the purpose of this chapter and unless otherwise required by the context:
  1.  “Book”, “list”, “record”, or “schedule” kept by a county auditor, assessor, treasurer, recorder, sheriff, or other county officer means the county system as defined in section 445.1.
  2.  “Court” means the district court in the county of the taxpayer’s residence.
  3.  “Department” means the department of revenue.
  4.  “Director” means the director of revenue.
  5.  “Internal Revenue Code” means the Internal Revenue Code of 1954, prior to the date of its redesignation as the Internal Revenue Code of 1986 by the Tax Reform Act of 1986, or means the Internal Revenue Code of 1986 as amended to and including January 1, 2011.
  6.  The word “taxpayer” includes any person, corporation, or fiduciary who is subject to a tax imposed by this chapter.
[C35, §6943-f3; C39, §6943.035; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §422.3]
84 Acts, ch 1305, §25; 85 Acts, ch 230, §3; 86 Acts, ch 1213, §8; 86 Acts, ch 1245, §439; 88 Acts, ch 1028, §1; 89 Acts, ch 285, §2; 90 Acts, ch 1171, §1; 91 Acts, ch 215, §1; 92 Acts, ch 1219, §1; 93 Acts, ch 113, §1; 94 Acts, ch 1166, §1; 95 Acts, ch 152, §2; 96 Acts, ch 1166, §2, 4; 97 Acts, ch 135, §3, 9; 98 Acts, ch 1078, §3, 10; 99 Acts, ch 95, §3, 12, 13; 2000 Acts, ch 1146, §3, 9, 11; 2000 Acts, ch 1148, §1; 2001 Acts, ch 127, §3, 9, 10; 2002 Acts, ch 1069, §3, 10, 14; 2002 Acts, ch 1119, §200, 201; 2003 Acts, ch 139, §3; 2003 Acts, ch 145, §286; 2004 Acts, 1st Ex, ch 1001, §37, 41, 42; 2005 Acts, ch 24, §3, 10, 11; 2006 Acts, ch 1140, §3, 10, 11; 2007 Acts, ch 12, §3, 7, 8; 2008 Acts, ch 1011, §3, 9; 2011 Acts, ch 41, §1, 5, 6
Internal Revenue Code definition is updated regularly; for applicable definition in a prior tax year, refer to Iowa Acts and Code for that year 
2011 amendment to subsection 5 takes effect April 12, 2011, and applies retroactively to January 1, 2010, for tax years beginning on or after that date; 2011 Acts, ch 41, §5, 6
Subsection 5 amended