Montana brokerage account growth calculator

What a taxable index-fund account is actually worth after expense-ratio drag and after Montana takes its share of the gain — which, in most states, is not at the federal preferential rate.

Montana taxes capital gains at its own lower rate

Montana is one of the minority of states that charges long-term gains at a lower rate than ordinary income. MONTANA IS ONE OF THE FEW STATES WITH A GENUINE PREFERENTIAL LONG-TERM CAPITAL GAINS RATE, and it is two-tier: 3.0% and 4.1% under MCA 15-30-2103(2), with thresholds identical to the ordinary brackets. THE RATE RECORDED HERE IS THE HIGHER TIER, DELIBERATELY. This schema carries one preferential rate, and the two tiers share a single stack with ordinary income sitting at the bottom — so the 3.0% band is available only to the extent ordinary income has not already consumed the bracket, and vanishes entirely once ordinary income exceeds the threshold. Recording 3.0% would understate the tax for most filers with meaningful ordinary income; 4.1% overstates it for filers with little. Treat a Montana capital-gains figure from this calculator as an upper bound. SHORT-TERM GAINS GET NO PREFERENCE and neither do QUALIFIED DIVIDENDS — Publication 1 defines Montana Ordinary Income as all taxable income that is not a net long-term capital gain 'and includes qualified dividends', a notable divergence from federal treatment. The old 2% capital gains CREDIT was repealed by SB 399 of 2021 and replaced by these rates.