The Trump administration has taken a first step to reshape Obamacare through its own administrative powers, even as Republicans on Capitol Hill remain stymied over how to repeal and replace the healthcare law.

A rule proposed on Wednesday, which would tighten up enrollment and allow plans across all tiers to cover fewer medical expenses, is likely to please health insurers facing deep marketplace uncertainty, and comes on the heels of an announcement Tuesday by major insurer Humana that it’s exiting next year due to heavy losses.