Are the dollar amounts showing up on my "Iowa Retirement Income" coming from last year's Turbotax submission? If not, where are they being pulled from?

Yes, those amounts may be coming from your 2023 return.  Since people often have the same retirement accounts year after year, but you don't have them this year, you can delete those items from your Federal return in the Retirement income section.  

 

This should correct your Iowa return.

 

If you're using TurboTax Online, clear your  Cache and Cookies first.

 

@ctq515