Insurance companies would bear the cost of providing the separate coverage, with the possibility of recouping the costs through lower health care expenses resulting in part from fewer births.

Chiquita Brooks-LaSure, who helped develop the proposal as deputy director of the federal office that regulates health insurance, said: “Under the proposed rule, insurance companies — not churches or other religious organizations — will cover contraceptive services. No nonprofit religious institution will be forced to pay for or provide contraceptive coverage, and churches and houses of worship are specifically exempt.”

Moreover, she said, “Nonprofit religious organizations like universities, hospitals or charities with religious objections won’t have to arrange, contract or pay for coverage of these services for their employees or students.”

But some of the lawsuits objecting to the plan have been filed by businesses owned by people who say they have religious reasons for not wanting to provide contraceptive coverage. Under the proposed rule, “for-profit secular employers” would have to provide birth control coverage to employees, even if the business owners had a religious objection to the idea.

Insurers said they were studying the proposal, but had questions about how it would work. Many insurers asked where they would get the money to pay for birth control pills if — as the proposed rule says — they cannot “impose any premium, fee or other charge” for the coverage. The 2010 health care law generally requires employers to provide women with coverage at no cost for “preventive care and screenings,” which the administration says must include contraceptives for women under most health plans.

The administration says employers must cover sterilization and the full range of contraceptive methods approved by the Food and Drug Administration, including emergency contraceptive pills, like those known as ella and Plan B One-Step. Employers that do not provide such coverage will be subject to financial penalties.

On Friday, the administration proposed a complicated arrangement to finance contraceptive coverage for employees of religious organizations that serve as their own insurers. The federal government would require health insurance companies to help defray the cost. In return, the insurers would get a credit against the fees they pay for the privilege of selling health insurance to millions of Americans in new online markets run by the federal government.