[5] The state of Montana passed a special income tax credit program in 2015 to help fund non-profit scholarship organizations to help low-income families pay for private schools.

[9] Three low-income families who had children attended Stillwater Christian School in Flathead County and would have been eligible for scholarships through the program outside of their school choice filed a lawsuit against the state and sought an injunction against the program, asserting that Rule 1 unnecessary against the no-aid provision and that it discriminated against them due to their religion under the First Amendment to the United States Constitution.

[9] The state began to appeal this ruling, but otherwise continued the program with the ordered injunction, which allowed additional scholarships to be granted for several children attending Stillwater.

The state's appeal to the Montana Supreme Court was decided in December 2018, which ruled in a 5–2 decision that the entire program was unconstitutional because it benefited religious schools.

The Justices focused on whether the Montana Supreme Court's decision to shut down the entire program was discriminatory towards the secular schools, as well as trying to resolve this case with recent decision related to the Free Exercise Clause, such as Trinity Lutheran Church of Columbia, Inc. v. Comer,[12] in which the Court previously ruled that blocking public funds to be used by a church to improve playground safety was a violation of the Free Exercise Clause.

"[17] Roberts also asserted that the Montana Supreme Court was wrong to invalidate the entire program on the basis of the no-aid provision in the state constitution.

Alito cited the Court's earlier decision in Ramos v. Louisiana,[21] in which judgement was partially based on the motivation of outdated Jim Crow laws in the nature of jury verdicts.

Montana's claim that the provision merely reflects a state interest in preserving public schools ignores that the public-school (or common-school) movement at the time was itself anti-Catholic.

Ginsburg, in her dissent, acknowledged to Roberts' point that states are not required to subsidize private education and in the case of Montana, their court discontinued the program, which does not affect the Free Exercise Clause.