WASHINGTON — Federal health officials are not enforcing requirements for Medicaid coverage of abortion in the limited circumstances where it is legal, congressional investigators have found.

At least 13 states are flouting a requirement to cover abortion-inducing pills, and one state, South Dakota, has for 25 years failed to provide the required coverage for abortion in cases of rape or incest, the Government Accountability Office, a nonpartisan investigative arm of Congress, said in a report made public this month.

The report underlines the wide range of restrictions that states impose on abortion access and Medicaid coverage of it.

Trump administration officials, like many of their predecessors, “have not taken any actions to address states’ noncompliance,” the report said.

The federal law known as the Hyde Amendment generally prohibits federal funding for abortions. But state Medicaid programs are required to cover an abortion if the pregnancy is a result of rape or incest, or if the life of the pregnant woman would be endangered without an abortion.

States are also supposed to cover the pill that induces abortion, Mifeprex, when an abortion is available under Medicaid. But in a survey by the Government Accountability Office, 13 states said they do not cover the drug.

“Without such coverage,” the report said, “Medicaid beneficiaries seeking abortions in these states would have to find another way to pay for the drug or undergo a surgical abortion instead.”

Federal officials at the Centers for Medicare and Medicaid Services “were not aware that these states did not cover Mifeprex, and thus the agency had not sought to address states’ noncompliance,” the report said.

The drug is approved for use through the first 10 weeks of pregnancy and is usually taken in combination with another medicine.

The findings lead to a paradoxical conclusion: The Trump administration, which is firmly opposed to abortion, may have to work with states to make sure they provide Medicaid coverage for the surgical procedure and for the abortion pill in certain circumstances.

After seeing a draft of the report, the Trump administration said it would urge states to comply because they must operate their Medicaid programs “in accordance with federal laws and guidance.”

This article originally appeared in The New York Times.