Lawmakers in Montana, Tennessee and Kansas have voted in the past few weeks to narrowly define who is "female" and who is "male" in state law using such terms as "gametes," "ova," "sex chromosomes," "genitalia" and "immutable biological sex."

The bills in Montana and Tennessee have passed the legislature and are headed to governors' desks. The Kansas bill, called the "women's bill of rights," was vetoed by Gov. Laura Kelly, a Democrat, but the Republican legislature was able to override her.

Advocates for LGBTQ rights say these bills are one more step in the ratcheting up of politics and policies against transgender and nonbinary people.

Republicans sponsoring the bills say the definitions are important to keep sex from being conflated with gender.

How the bills define 'sex'

The Montana chapter of the American Academy of Pediatrics says the bill language in that state is scientifically inaccurate and that it isn't inclusive of people with chromosomal variations, such as intersex people, or people with diverse gender identities, such as transgender or nonbinary people.

The bill is based on a person's chromosomes and whether or not they produce eggs. A "female" produces eggs and a "male" produces sperm. The bill also includes language that there are exactly two sexes.

But research shows that sex can be more complicated than just male or female. Sex chromosomes can indicate one thing, anatomy can indicate something else and other genetic factors can play a role.

The Kansas law legally defines a woman as someone whose reproductive system is designed to produce ova, and a man as someone whose reproductive systems are designed to fertilize ova.

In Tennesee, the language used to define sex is "a person's immutable biological sex as determined by anatomy and genetics existing at the time of birth."

"When this body has used the term 'sex' in the Tennessee code over the years, it has, in fact, referred to one's biological sex," said Republican state Rep. Gino Bulso on the House Floor. "It has meant male or female. It has meant men or women. It has meant boys or girls," he added.

LGBTQ advocates, like Naomi Goldberg at the Movement Advancement Project, say there is no need to clarify sex in state code.

"Fewer people know someone who is trans than know someone who is gay or lesbian, for example," says Goldberg, "so there is an opening there for opponents to introduce misinformation, to introduce concerns about realities that merely do not exist."

Effects on transgender, nonbinary and intersex people

Come July 1, the estimated 2% of Kansans who are transgender will live under the "women's bill of rights." The law essentially blocks legal recognition of their gender identity and forces them to use the bathrooms, locker rooms and other public facilities of the sex they were assigned at birth.

For transgender, nonbinary or intersex people, having identification that's incongruent with their identity could open them up to discrimination and possibly subject them to violence in unsafe situations, if they're outed.

"This bill is not just unnecessary, it's harmful," said Montana state Rep. SJ Howell on the House floor. Howell is a Democrat who identifies as transgender nonbinary.

"And one of things that I love about Montana is that it is big enough. And not just big enough in acreage, but big enough in character. I think Montana is big enough to understand that we do not need to define people in this way."

Howell said they prefer to keep their private life private, but that this bill won't allow them to do that. The bill in Montana affects 41 sections of code, so opponents say it's impossible to know all of the implications of it, intended or not. It'll require state agencies across the board, like the state's health department and corrections department, to update their rules and how they interact with residents.

Discrimination and budget implications

In Montana, nonpartisan fiscal analysts say the bill could risk up to $7 billion the state receives from the federal government because of federal anti-discrimination rules tied to that money.

The federal government uses the power of its purse to force compliance with federal rules, which protect people on the basis of sex and gender identity, but there's no exact formula for how that could happen. Generally, when the federal government threatens to pull funding, it goes to the courts.

"Often that would end in some sort of resolution agreement where no money is actually lost" says Eloise Pasachoff, a law professor at Georgetown University. "The threat of the money actually being lost, which is a real threat, is what helps the parties reach a real settlement."

Pasachoff says it's plausible that the federal government could pull some, or all of the state's federal dollars if they can't agree to a settlement.

Fiscal analysts in Tennessee have said it could cost the state more than $2 billion in federal funding grants from the U.S. Department of Education and Department of Health.

The Kansas law could result in domestic violence and rape crisis centers losing access to federal grants by forcing them out of compliance with anti-discrimination rules. In a hearing, the executive director of the Kansas Coalition Against Sexual and Domestic Violence said it could jeopardize up to $14 million per year.

The state's Democratic governor, Laura Kelly, is also warning of a different kind of financial fallout. She has warned the law could harm the state's economy as it struggles to entice employers and deals with severe shortages of critical workers, particularly in health care and education.

"Companies have made it clear that they are not interested in doing business with states that discriminate against workers and their families," she said in a statement explaining her veto of the "women's bill of rights" and several other bills.

Could these bills stand up to litigation?

In Bostock v. Clayton County, the U.S. Supreme Court ruled that discrimination based on gender identity falls under sex discrimination, so some legal experts say the bills have very little to stand on.

In both Tennessee and Kansas, the ACLU could take the legislation to court. In Kansas, the attorney general's office said it expects that the law there will be challenged.

In 2021, the Montana Legislature passed restrictions on birth certificate amendments for transgender people. It was challenged in court, and while the court is still working through the issue, a district court judge temporarily blocked that law saying it's likely violating the constitutional right in the state to equal protection and privacy.

In that order, Republican lawmakers argue the judge conflated sex and gender when the judge wrote the law likely discriminates based on gender. Republicans now say that's why Montana needs a law defining sex.

Shaylee Ragar is Montana Public Radio's capitol bureau chief, Blaise Gainey is a political reporter with WPLN and Rose Conlon is a health reporter with The Kansas News Service. Acacia Squires, the NPR States Team editor, also contributed to and edited this story.