Conservative religious schools all over the country forbid same-sex relationships, from dating to couples’ living in married-student housing, and they fear they will soon be forced to make a wrenching choice. If the Supreme Court this month finds a constitutional right to same-sex marriage, the schools say they will have to abandon their policies that prohibit gay relationships or eventually risk losing their tax-exempt status.

The religious schools are concerned that if they continue to ban gay relationships, the Internal Revenue Service could take away their tax-exempt status as a violation of a “fundamental national public policy” under the reasoning of a 1983 Supreme Court decision that allowed the agency to revoke the tax-exempt status of schools that banned interracial relationships.

In a recent letter to congressional leaders, officials from more than 70 schools, including Catholic high schools and evangelical colleges, said that a Supreme Court ruling approving same-sex marriage would put at risk all schools “adhering to traditional religious and moral values.”

“I am concerned, and I think I’d be remiss, if not naïve, to be otherwise,” said Everett Piper, the president of Oklahoma Wesleyan University, in Bartlesville. “This is not alarmist thinking. This is rational listening.”