Stillwater Insurance Company has filed changes to its businessowners insurance program in Michigan, including new coverage options and an average rate increase of 21.1% for its small existing book.

The insurer currently has just three in-force businessowners policies in the state, representing $10,829 in written premium. The increases range from 9.1% to 38.5%, generating approximately $2,169 in additional premium. Stillwater said the 21.1% average is not representative of its broader rate position, noting that ISO calculated a statewide impact of 9.7% from the revised loss costs.

Stillwater is also introducing miscellaneous professional liability coverage for more than 100 business classes. The coverage replaces six ISO professional liability forms, although the insurer is not formally withdrawing those forms.

Other additions include crisis care coverage for incidents involving threats or serious physical harm in the workplace and commercial service line coverage for exterior underground pipes and wiring.

The filing also adds 20 business class codes, including classifications for spas, online retailers, ophthalmologists and optometrists. Online retailers will be rated according to the products they sell instead of as office risks.

Additional changes include increasing the nonsufficient-funds fee from $15 to $25, applying a communicable disease exclusion to all policies and allowing sales and payroll figures to be adjusted for inflation.

The filing was submitted on July 27 and remains pending. Stillwater is requesting effective dates of August 28, 2026, for new business and October 2, 2026, for renewals.