This ProSeries error has never been fixed! I am having to zero out the deduction for all health insurance premiums, including Medicare premiums, on Iowa Line 15. The client I am working on was able to itemize on federal, so if anything, he should only deduct the amount disallowed for percent of AGI reduction, or maybe not even that. 

I will say the Iowa 1040 instructions are not helpful in explaining this and will have many people making this same error. I was able to confirm my decision at Iowa DOR online where I found the following:

"Similar to previous tax years, this deduction is allowed to the extent that the health insurance is not otherwise deducted in computing federal taxable income. In other words, an additional deduction is not allowed if the same health insurance premiums are deducted as a self-employed health insurance deduction or as an itemized deduction."

Come on, ProSeries! Pay attention and get this corrected as it will probably be the same next year.