A federal judge blocked Medicaid work requirements in two states on Wednesday, dealing a blow to one of the Trump administration's marquee efforts.

U.S. District Judge James E. Boasberg in Washington issued two decisions finding that Medicaid work requirements for low-income people in Arkansas and Kentucky pose numerous obstacles to getting health care that haven't been adequately resolved by federal and state officials.

Judge James E. Boasberg US District Court of Columbia

He sent the federal Health and Human Services Department back to the drawing board.

Work requirements are already in effect in Arkansas, but Kentucky's program has been on hold because of lawsuits. Both states want "able-bodied" adults who get health insurance through the Affordable Care Act's Medicaid expansion to work, study, volunteer or participate in "community engagement" activities.

But advocates for the poor say that Medicaid is a health care program and that work requirements have no place in it. Boasberg did not resolve that core issue.

Instead, he wrote that HHS approval of the Arkansas requirement was "arbitrary and capricious because it did not address ...whether and how the project would implicate the 'core' objective of Medicaid: the provision of medical coverage to the needy."

He used similar language in his ruling on Kentucky.

Nationally, some 12 million people are covered by the Medicaid expansion, accepted now by more than 30 states. Officials in GOP-led states have argued that work requirements and other measures such as modest premiums are needed to ensure political acceptance for the expansion.

The Trump administration early on encouraged states to apply for Medicaid waivers that would allow work requirements.

Eight states have had their requests approved, though not all have put their programs in place, according to the nonpartisan Kaiser Family Foundation. Requests from seven others are pending. In one of those states, Virginia, a work requirement was key to getting the legislature to approve Medicaid expansion.