Appearing in court over a federal judge’s ruling that its wellness rule for company health plans penalized non-participating employees, the Equal Employment Opportunity Commission (EEOC) this week argued that vacating the rule would create “chaos” for companies eyeing health plans for 2018.

In August, U.S. District Judge John Bates sided with the AARP in its lawsuit against the EEOC, alleging the rule is inherently unfair because it allows employers to incentivize participation by allowing up to a 30-percent reduction in insurance premiums for participants.

Bates did not toss the rule but sent it back to the EEOC for review and revision. Following his ruling, the AARP then asked for the wellness rule to be vacated before it takes effect next Jan. 1.¬†Alternatively, AARP lawyers argued, Bates could issue a “prospective injunction” against enforcement of the rule effective Jan. 1, 2018.

In court, attorneys for the agency said it could not finish the review process by the end of the year and urged the judge not to vacate the rule because it would upend company benefit planning nationwide.