Governor Greg Gianforte stood at the Montana State Capitol in Helena on September 8 to formally launch a campaign pushing a 4.7 percent flat income tax for Montana, joining the Mountain States Policy Center in an effort to build public support ahead of the 2027 legislative session. The announcement was reported by the State of Montana Newsroom.
The Campaign and Its Goals
The initiative, branded Flat. Fair. Montana., is a joint effort between Gianforte’s office and the Mountain States Policy Center (MSPC). MSPC President and CEO Chris Cargill and Jack Baum of Americans for Tax Reform appeared alongside the governor at the Capitol event.
The proposed rate — 4.7 percent — matches Montana’s current lower income tax bracket. Supporters argue consolidating all taxable income into a single rate at that level would simplify the code and deliver measurable economic benefits to working Montanans.
An independent economic analysis cited by the campaign projects that adopting the flat rate could expand Montana’s gross state product by roughly $525 million, add approximately $286 million in wages, create more than 2,400 jobs, and put nearly $650 more in after-tax income into the average Montanan’s pocket annually.
Where Montana Stands Now
When Gianforte took office, Montana’s top individual income tax rate stood at 6.9 percent and the state used seven separate brackets. The governor has since reduced the top rate and collapsed the bracket structure to two tiers. Legislation signed in 2025 set the rate at 5.65 percent for 2026, with a further reduction to 5.4 percent scheduled to take effect in 2027.
Even at 5.4 percent, Montana will remain above several neighboring and regional competitors. Idaho’s flat rate is 5.3 percent, Utah’s is 4.5 percent, Colorado’s is 4.4 percent, and Arizona’s is 2.5 percent. Wyoming and Nevada impose no individual income tax at all.
Gianforte and MSPC point to a broader national trend: since 2021, more than two dozen states have cut their income tax rates. Of the states that still levy an income tax, seventeen now use a flat rate, and ten of those made the switch within the past decade.
Montana’s fiscal health ranking has improved from 22nd in 2021 to 8th today, and state income tax revenue has doubled over the same period — figures the governor’s office cites as evidence that rate reductions have not undermined the state’s finances. An MSPC survey found that roughly 60 percent of Montanans express concern about the state’s income tax rate.
Building Toward 2027
The campaign is designed to generate public momentum before the 2027 legislative session, when any statutory rate change would need to be enacted. Gianforte has previously outlined the flat tax as a priority for that session, and this week’s event marks a more formal, organized push to make the case to voters and lawmakers alike.
MSPC plans to hold town hall meetings across Montana in the coming weeks to explain the proposal and gather public input. The organization’s involvement signals that the effort will extend beyond the Capitol and into communities statewide before legislators convene.
The 2025 session’s tax legislation also doubled the earned income tax credit, a provision supporters used to argue the overall package benefited lower-income workers alongside higher earners — a framing likely to resurface as the flat tax debate intensifies heading into 2027.
