Michigan Treasury Issues Notice on Supreme Court Ruling for Insurer UBG Tax Liability

The Michigan Department of Treasury issued a notice to taxpayers regarding the Michigan Supreme Court’s decision in Nationwide Agribusiness Ins Co v Dep’t of Treasury, which addressed whether unitary business groups (UBGs) of insurance companies must file combined returns for premiums and retaliatory tax liabilities. The Supreme Court declined to review the Court of Appeals’ 2024 decision, which held that UBGs of insurers must file unitary returns calculating these tax liabilities at the UBG level. This decision applies to all open tax years and to the 2025 tax year, with upcoming filing deadlines. Impacted insurers are encouraged to request an ...