Montana House GOP Holds Sex Definition Bill to Avoid Court Challenges

HELENA — House Republican leadership is strategically holding Senate Bill 437, which defines sex in Montana law, to prevent the legislation from being immediately challenged alongside other gender-related laws already facing court battles.

“Montanans sent us here to make law, not to let activist judges tear it down the moment the ink dries,” said Speaker Ler in a statement released Monday. “We refuse to hand the judiciary an easy path to lump these cases together and stall the will of the people. That’s why we are being deliberate with the timing on SB 437.”

The bill, which has passed both legislative chambers, remains unsigned on the House Speaker’s desk rather than being transmitted to the governor for signature—a strategic move designed to keep it separate from ongoing litigation over similar legislation.

Legal Battlefield

House GOP leadership is navigating a complex legal landscape involving multiple laws related to the recognition of biological sex as a clearly defined standard that have faced court challenges:

SB 458 (2023), Montana’s previous sex definition law, established biological definitions of “male,” “female,” and “sex” and applied these definitions across dozens of sections of Montana Code, from employment discrimination to vital records to criminal law. The comprehensive legislation was struck down twice—first in June 2024 on procedural grounds for violating the state constitution’s single-subject rule, then again in February 2025 when Judge Leslie Halligan ruled it unconstitutional on privacy and equal protection grounds. The state has appealed to the Montana Supreme Court.

House Bill 121 (2025), requiring sex-segregated bathrooms, locker rooms, and sleeping quarters in public facilities, was blocked by Judge Shane Vannatta in April. Vannatta issued a temporary restraining order against the women’s privacy law, calling it “motivated by animus.”

In July, Judge Vannatta also ordered taxpayers to pay nearly $100,000 in attorney fees to plaintiffs’ legal teams for successfully challenging SB 458.

Strategic Timing

Speaker Ler’s statement directly addresses the pattern of adverse court rulings, criticizing what he characterized as judicial overreach.

“Let’s be clear: the problem isn’t lawmakers doing their job. The problem is a judiciary that has become more interested in playing politics than upholding law,” Ler continued. “By holding SB 437, we’re making sure this legislation has the strongest chance to stand. We will not sit back while partisan judges try to erase what the people’s representatives have enacted.”

The current bill, SB 437, mirrors previous efforts to establish biological definitions of sex in state law. Like its 2023 predecessor, SB 437 defines “sex,” “male,” “female,” “man,” “woman,” “father,” and “mother” based exclusively on biological characteristics and applies these definitions throughout Montana Code, clarifying that legal references to sex refer to biological sex rather than gender identity. Montana lawmakers have consistently pursued such legislation, arguing it provides necessary legal clarity and reflects strong public support.

Procedural Questions

The legislative strategy raises questions about procedural limits on how long passed legislation can be held. The Montana Legislature adjourned sine die on April 30, 2025, potentially creating constraints on the House’s ability to indefinitely delay transmitting the bill to the governor.

House Republican leadership confirmed to Western Montana News that they can hold the legislation indefinitely, stating “There’s nothing in statute that compels us to move it. No special session planned.” This clarifies that sine die does not create procedural constraints on holding passed legislation, making their strategic timing approach legally viable.

Legal Context

The litigation concerns stem from organized challenges by groups including the ACLU, which has successfully blocked or overturned previous Montana laws defining sex in biological terms. These cases often involve out-of-state funding and legal networks that treat Montana as what critics call a “proving ground” for gender ideology enforcement.

The House GOP statement emphasized their commitment to eventual passage: “SB 437 will ultimately be signed into law. House leadership will not apologize for taking the necessary steps to protect Montanans’ values from a judiciary that too often substitutes ideology for the Constitution.”

The strategic hold represents an unusual legislative maneuver designed to maximize the bill’s chances of surviving court challenges while avoiding consolidation with existing litigation that has already resulted in adverse rulings for similar Montana laws.