Free Montana (MT) income tax calculator with 2026-specific rates. Calculate your exact income tax using real Montana data.
Montana has a top marginal income tax rate of 5.9%. The state uses a progressive tax system with 2 brackets.
Montana uses a progressive income tax system with 2 brackets ranging from 4.7% to 5.9%.
Montana residents must file a state income tax return with the Montana Department of Revenue (or equivalent agency). Most taxpayers can file electronically. The deadline typically aligns with the federal tax deadline of April 15.