An answer shall show on whose behalf it is filed and specifically admit, deny, or otherwise answer all material allegations of the notice of hearing. It shall state any facts deemed to show an affirmative defense and contain as many additional defenses as the pleader may claim.
Any allegation in the notice of hearing not denied in the answer is considered admitted. The presiding officer may refuse to consider any defense not raised in the answer which could have been raised on the basis of facts known when the answer was filed if any party would be prejudiced.
Iowa Admin. Code r. 875-1.74