Stillwater Insurance Company submitted a rate and rule filing for its Businessowners program in Idaho, proposing an overall rate increase of 9.4% across a small book of 34 policies representing about $39,500 in written premium. The changes are scheduled to take effect March 2, 2026 for new business and April 6, 2026 for renewals.

The update introduces a new Miscellaneous Professional Liability endorsement that expands professional liability availability to nearly 100 business classes. The company is also adopting updated ISO Businessowners loss costs and implementing a more granular pricing approach that separates property risk into individual peril components, including fire, theft, water, wind, and hurricane. Base loss costs will be determined at the Census Block Group level when available.

Additional changes include revisions to payment rules, a clarified paid in full discount, and the removal of several hundred unused class codes with no impact to existing renewals or underwriting appetite. The filing reflects a broader shift toward more detailed risk segmentation and expanded coverage options for small business customers.