State tax filing
Nonresidents of Montana are taxed on their Montana sourced income. However, this tax is first calculated based on taxable income determined as if the taxpayer was a resident, and then apportioned to the amount of Montana source income included in Montana Adjusted Gross Income. This apportionment is determined using the Nonresident/Part-Year resident Ratio Schedule. I put a screenshot of the schedule below. Therefore, it may appear as if you are being taxed on your entire amount of income, but you really are not. They are allocating your income towards the end of the return.
To specify, your nonresident ratio (which is your Montana income divided by your total income) is calculated on Form 2, page 8. You will then see your tax liability for your Montana income on Form 2, line 18.
