Montana Supreme Court denies Gov. Gianforte's request to expedite property tax lawsuit

The Montana Supreme Court on Tuesday unanimously rejected Gov. Greg Gianforte's request to expedite a lawsuit against the major property tax relief bill passed at the 2025 Legislature.

While the governor urged the high court to take the case to minimize potential disruptions to the property tax system, justices wrote on Tuesday that Gianforte hadn't properly established a reason to vault the normal district court proceedings.

Those who challenged the GOP governor's property tax reform are Republicans themselves — Sen. Greg Hertz, Sen. Tom McGillvray and former Sen. Keith Regier. They brought the lawsuit earlier this year claiming that Senate Bill 542 violates two provisions of the state’s constitution.

The new laws born out of SB 542, which was sponsored by Sen. Wylie Galt, R-Martinsdale, already went into effect for the 2025 tax year, and were responsible for $400 property tax rebates — totaling $95 million — and lower property taxes for 80% of homeowners. The new laws are also set to govern 2026 taxes. Most of the core tenets of SB 542 came from Gianforte's property tax task force he formed to tamp down spikes in property taxes, but the bills to implement these changes garnered stiff opposition from a certain faction of Republicans that at times included McGilvray and Hertz.

In a March court filing, Gianforte urged the Montana Supreme Court to take up the case, which would elevate it from its current proceedings in Gallatin County District Court. Gianforte argued that the case could wreak havoc on a property tax system that’s already in effect, and put 2027 legislators in a bind if this is not settled by then.

But the Supreme Court justices said the district court is equipped to handle the matter and declined to expedite the process.

"...we are confident that the District Court, which is well-equipped to consider the legal questions Governor Gianforte posits, may resolve the legal issues in a timely fashion and provide opportunity for appeal so long as the parties diligently litigate the case," the order from the justices read. "Moreover, nothing precludes the Legislature from considering the issues raised in the current District Court litigation as guidance as to how it may avoid similar challenges to its bill process in the 2027 legislative session."

The order explained that the justices can deny this type of request when the petitioner fails to demonstrate that "urgency or emergency factors" of the case make the typical appeal process inadequate.

"The governor is disappointed the Supreme Court is refusing to step in to ensure the significant property tax relief provided to Montanans remains intact," Kaitlin Timken, spokesperson for the Gianforte, said in an emailed statement. "If the lawsuit succeeds in the lower courts, it could potentially invalidate the tax rates applied in the 2025 tax year and roll back about $95 million in property tax rebates claimed by Montanans last year, resulting in higher property taxes for Montanans."

As the governor's office expressed concern about the timeline of this case, Hertz blamed Gianforte's office for further delaying the proceedings.

"It is unfortunate the Governor’s attorneys have spent weeks with this action in the Supreme Court and have failed to reply to our lawsuit in District Court," he said in a text message. "They have now requested almost 4 weeks of delays. If the governor wants to get this resolved, he needs to direct his attorneys to file their responses in a timely manner and stop the delay tactics."

Hertz, McGilvray and Regier argue that SB 542 was altered too far from its original purpose during the lawmaking process, and that it combined too many “independent and incongruous” provisions into one law, both of which they say violate the Montana Constitution.

The original language of SB 542 would have frozen property valuations, but it had the broad title of “generally revising tax laws.” Under the state's constitution, a bill's language has to conform with its title, so legislators will purposefully put a broad title on a bill as a strategy to maintain it as a landing area to amend in their policy priorities in case other bills get voted down.

And that is precisely what happened with SB 542: The bill was gutted entirely, and inserted into it were dozens of pages from another property tax bill.

Matthew Monforton, attorney for the Republican legislators, said in a statement for this story that SB 542 "wasn't tax reform — it was a rushed rewrite pf a bill that couldn't survive normal scrutiny."

"The Supreme Court's decision not to step in early speaks volumes," he added.