ST. LOUIS — A coalition of more than 40 state and national advocacy organizations is urging Missouri lawmakers to modernize the state’s tax code and support Gov. Mike Kehoe’s proposal to phase out the individual income tax, arguing that Missouri’s current system is outdated, overly complex and no longer reflects how residents live and work.
The appeal is presented in a January 5 letter addressed to members of the Missouri General Assembly and led by the National Taxpayers Union, with endorsements from groups including The Freedom Principle MO, the Center for Individual Freedom, Americans for Prosperity-Missouri and others.
The organizations express “strong support” for Kehoe’s “Missouri Promise” initiative, which calls for replacing the state’s 1931-era income tax structure with a system designed for the modern economy.
According to the letter, Missouri’s current tax code was designed during the Great Depression, when economic conditions, income levels and the structure of work were dramatically different.
The coalition notes that in 1931, average Missourians earned only a few hundred dollars a year and that technological, demographic and economic realities have since changed, while the underlying tax framework has largely remained the same.
One of the central criticisms raised in the letter is that Missourians earning just over roughly $9,000 annually are subject to the state’s top income tax rate, a threshold the groups describe as disconnected from today’s income levels.
The letter also points to the state’s sales tax system, which includes 216 exemptions, more than 2,526 separate taxing jurisdictions and decades of industry-specific carveouts, as an example of a code that has become “a dense, outdated patchwork” over time.
Byron Keelin, president of the Freedom Principle MO, said that his organization is “honored to join this expansive coalition” in advocating for reform that he said would put more money back into the pockets of Missourians, attract families and businesses and promote economic growth.
He expressed hope that Kehoe’s approach to phasing out the income tax with safeguards would mirror strategies used in other states and help make Missouri more competitive.
The letter frames Missouri’s debate within what it describes as a broader national trend toward lower and simpler income taxes.
It says that nine states no longer levy a broad-based individual income tax and that more than two dozen states have reduced rates, adopted flat taxes or implemented phase-outs in recent years.
The organizations argue that this movement spans both Republican- and Democratic-led states and represents a mainstream shift in fiscal policy rather than a fringe idea.
To support their position, the coalition cites economic and demographic data comparing zero-income-tax states with high-tax states over the past decade.
According to the letter, zero-income-tax states averaged 11.8% population growth, 6.4% net domestic migration gains, 15.9% job growth, 67.1% personal income growth and 66.6% gross state product growth, all exceeding the corresponding figures in high-tax states.
The letter also references states that adopted income taxes between 1961 and 1991, asserting that each of those states saw declines in their share of the national population, economic output and tax revenue.
Ohio, Michigan and West Virginia are cited as examples of states that experienced significant decreases in population share and economic output over that period.
While acknowledging criticism rooted in Kansas’ tax policy changes of the early 2010s, the coalition argues that those reforms lacked spending discipline and structural safeguards and should not be used to justify inaction in Missouri.
The letter notes that Kansas later adopted a different reform approach and that other states have implemented multi-year, trigger-based reforms designed to protect budgets while reducing rates.
The organizations urge lawmakers to publicly endorse the goal of phasing out the income tax, work with the governor to design a “path to zero” that includes revenue triggers and spending discipline, and reject efforts to preserve narrow tax carveouts or derail reform.
They describe the proposal as an opportunity for Missouri to move from a Depression-era tax system to a 21st-century model that rewards work, attracts families and businesses and provides sustainable revenue for core services.
The letter concludes by stating that the undersigned organizations stand ready to work with the governor and legislators to make the Missouri Promise a reality, positioning the effort as a coordinated push for broad, structural tax modernization rather than incremental adjustments.
