After signaling for months that it was going to crack down on abuse of special enrollment periods, the Obama administration announced this week that it would be requiring those signing up for Patient Protection and Affordable Care Act (PPACA) plans to provide proof that they couldn’t sign up during the open enrollment period.

The decision is in response to complaints from insurers that people who have declined to get coverage during the open enrollment period have been signing up for plans only after they get sick by using the special enrollment exemptions. Insurers say that data shows that those who sign up through special enrollment cost more, on average, than other customers. As a result, a number of major insurers have told brokers that they won’t pay commissions for special enrollment customers.

“We are committed to making sure that special enrollment periods are available to those who are eligible,” Kevin Counihan, the CEO of Healthcare.gov, told the New York Times. “But it’s equally important to avoid misuse or abuse.”