The Legislative Services Agency (formerly the Legislative Services Bureau) maintains bill request/drafting files, which include:
LSA retains bill request files for the current General Assembly plus the prior General Assembly. However, these files are considered confidential and are not available for viewing until they go to the archives, unless permission is granted by the bill sponsor. The archives go back to 1967 and are kept in the State Archives, in the State of Iowa Historical Building. The archives are open to anyone. The materials can be used on premises only. To see a file, call the State Historical Society of Iowa Library during reference hours and speak to a librarian. They can have materials pulled from the archives for you to use in person in the reading room. When you talk to the librarian, you will need to know:
The State Historical Society of Iowa has an extensive collection, including the state archives (records "produced from government functions and activities").
You can search their online catalog or contact reference staff for additional guidance.