WHEN BUSINESS owners enter the public marketplace, they should expect to follow laws with which they might disagree, on religious or other grounds. This is particularly true when they form corporations, to which the government offers unique benefits unavailable to individuals.

The Supreme Court weakened that principle Monday. Congress should revitalize it.

The justices ruled on the Affordable Care Act’s contraception mandate, which requires employer-based health insurance policies to provide contraception to covered employees. Several corporations challenged the law, insisting that the mandate unlawfully infringes on their owners’ religious rights. In a 5 to 4 ruling, the court agreed with the corporations, which included Hobby Lobby, a large arts and crafts chain, and Conestoga Wood Specialties, a cabinetmaker.

By historical accident, the country has based its health-care system on employers arranging for their employees’ coverage. Transforming that system would have been disruptive, so President Obama’s Affordable Care Act largely sustained it, with Congress mandating that large and medium businesses offer essential benefits in their health plans.

But the court demanded Monday that the government accommodate corporation owners who bring their religious convictions into the public sphere. Some accommodations might be expensive, Justice Samuel A. Alito Jr. admitted in the majority opinion, but that’s not the court’s main concern. Neither, apparently, is the fact that some corporate owners will likely continue to object to workarounds, leading to more lawsuits.

The Supreme Court building following the court's decision on the Hobby Lobby case in Washington, Monday, June 30, 2014. The Supreme Court says corporations can hold religious objections that allow them to opt out of the new health law requirement that they cover contraceptives for women. (Pablo Martinez Monsivais/AP)

What else might courts now require in the name of corporations’ religious liberty? Justice Alito discouraged speculation that the court’s decision will lead to the weakening of other public health mandates, such as those covering vaccines or blood transfusions. Even if corporations enjoy religious protections, he wrote, the court must apply a balancing test before requiring exceptions, a balancing test the contraception mandate — and, at this point, only the contraception mandate — did not pass.

But that balancing test may be tough for the government to satisfy in other circumstances, too, if it is applied as aggressively as the court did in this instance. The public health case for the contraception mandate is strong. Institute of Medicine experts recommended universal contraceptive coverage. In the context of the employer-based system, the place to accomplish that is in the government’s broader benefits policy. The resulting imposition on religious business owners, meanwhile, was small. The mandate does not force them or any of their employees to use the birth control methods to which they object.

If this is the sort of balancing that the Supreme Court will conduct, Congress should change the law. The Constitution generally does not require religious exceptions to generally applicable laws. The ruling relied on the Religious Freedom Restoration Act, a statute that does not mention corporations and that lawmakers could easily narrow. They should not only guarantee contraception coverage but also repair the federal government’s ability to provide for wholly legitimate common goods such as public health and marketplace regulation.