The House Ways and Means Committee advanced a bill Wednesday that would require people who improperly receive insurance subsidies under the Affordable Care Act to repay the overpayments.

The bill, offered by Rep. Lynn Jenkins (R-Kan.), was approved by a vote of 22-14.

Jenkins told the committee the measure was a “simple bill,” about “good governance” and the “duty to protect the tax dollars of hardworking Americans.”

Enrollment in exchange coverage increased from 6.3 million at the end of 2014 to about 8.8 million, according to figures released by the administration at the end of last week.

But Obamacare’s coverage gains have also been more modest than expected, particularly when it comes to the exchanges. And part of the problem seems to be that people who sign up for coverage at the beginning of the year don’t always follow through to keep their coverage effective at the end of the year. It’s a problem that seems to be larger than the administration knew.

Along with releasing end-of-the-year 2015 enrollment data for the Affordable Care Act exchanges last Friday afternoon, the Department of Health and Human Services also released data for the 2016 open enrollment period. Just like the end-of-the year 2015 enrollment data, which I discussed on Monday, a close look at the 2016 open enrollment data reveals that the ACA is significantly underperforming initial expectations.

The big story is how little has changed from 2015 to 2016. The number of 2016 exchange enrollees is up only slightly from last year, and the make-up of the risk pool—as proxied by income and age of enrollees—is virtually identical.

Vermont has filed a 1332 state innovation waiver to avoid building a website for its small-business insurance exchange. The state hopes to have those employers enroll directly through insurers.

Under the waiver, beginning Jan. 1, 2017, states can request that the federal government waive basically every major coverage component of the Affordable Care Act, including exchanges, benefit packages, and the individual and employer mandates. The only requirement is that a state’s healthcare coverage remains consistent and adequate. Vermont is the first state to send a finalized request (PDF) to the CMS.

House v. Burwell is far from resolution, but this case’s path through the federal courts and the threat it could pose to the Affordable Care Act show continued vulnerabilities of the health-care law as well as the stakes of the 2016 election.

A Commonwealth Fund report published Thursday looks at a provision in the health-care law that is at issue in the case. To soften the impact of out-of-pocket costs under Obamacare, the law requires insurers to reduce certain payments for individuals whose incomes are up to 250% of the federal poverty level if they purchase a “silver” plan through one of the insurance marketplaces. The law also says that insurers are to be repaid for the discounts.