Iowa Code § 616.10: Insurance companies.

Insurance companies may be sued in any county in which their principal place of business is kept, or in which the contract of insurance was made, or in which the loss insured against occurred, or, in case of insurance against death or disability, in the county of the domicile of the insured at the time the loss occurred, or in the county of plaintiff’s residence. As used in this section the term “insurance companies” includes nonprofit hospital service corporations and nonprofit medical service corporations which have incorporated under the provisions of chapter 504, Code 1989, or current chapter 504.