After a decade of hard-won tax reform, Iowa lawmakers face a simple question this session: how do they ensure those gains aren’t undone by future legislatures?
Now that the 2026 legislative session is underway, the Iowa Legislature has an opportunity to advance two significant taxpayer protections designed to complement the state’s recent tax reforms. The first would require a two-thirds supermajority vote of both legislative chambers to increase income taxes. The second would constitutionally protect Iowa’s flat income tax by limiting the state to a single tax rate.
Public support for these protections is strong. Polling shows that 71 percent of Iowans favor requiring a two-thirds vote of the legislature to raise income taxes. Support extends across party lines, with 77 percent of independents and even a majority of Democrats—56 percent—backing a supermajority requirement. This level of consensus underscores a shared desire for predictability and restraint when it comes to tax increases.
A supermajority requirement to raise taxes is neither new nor controversial. Seventeen states already have similar provisions in place, including states with very different political cultures such as California and Arizona. These rules are intended to ensure that tax increases occur only when there is broad agreement that they are necessary.
In practice, a supermajority requirement encourages lawmakers to fully justify any proposal to raise taxes and often necessitates bipartisan support. It also serves as an indirect spending restraint. When raising taxes becomes more difficult, legislators are more likely to examine existing spending, prioritize programs, and seek efficiencies before turning to taxpayers for additional revenue.
Protecting Iowa’s flat income tax is the second key taxpayer safeguard under consideration. In January 2025, Iowa’s 3.8 percent flat tax was fully implemented, marking the culmination of a decade-long effort to simplify the tax code and improve the state’s economic competitiveness. The flat tax benefits taxpayers by providing a simpler, more transparent system with fewer distortions and clearer incentives for work, saving, and investment.
Constitutional protection would help prevent future legislatures from reverting to a progressive or multi-rate income tax system. It would also make it more difficult to increase the flat tax rate, providing taxpayers with additional assurance that the gains achieved through recent reforms will not be easily undone. Such safeguards could also help guard against proposals that would introduce new forms of taxation, such as wealth taxes, that could undermine Iowa’s economic climate.
Taxpayer protections are an essential complement to pro-growth tax reforms. While lower tax rates help improve competitiveness and encourage growth, protections ensure that those gains are durable. Enshrining limits in the Iowa Constitution would provide long-term stability by restraining government growth and keeping tax policy aligned with taxpayers’ ability to pay.
As former Senate Majority Leader Jack Whitver has noted, “Constitutional amendments to require a flat tax and a supermajority to raise taxes give Iowans the confidence to know state government will stay within its means, and taxes will remain low, fair, and structured to promote growth.”
Ultimately, the purpose of taxation is not wealth redistribution, but to fund essential government services in a way that does not hinder economic opportunity. Advancing these two taxpayer protections would help ensure Iowa remains fiscally responsible, competitive, and accountable to the people who fund state government.
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